diff --git a/litellm/litellm_core_utils/prompt_templates/common_utils.py b/litellm/litellm_core_utils/prompt_templates/common_utils.py
index 6287dc17e8f..3090281127b 100644
--- a/litellm/litellm_core_utils/prompt_templates/common_utils.py
+++ b/litellm/litellm_core_utils/prompt_templates/common_utils.py
@@ -3045,6 +3045,19 @@ def merge_consecutive_system_messages(
     ]
 
 
+_TOOL_USE_ID_FALLBACK: Final = "tool_use_id"
+_ANTHROPIC_TOOL_USE_ID_INVALID_CHARS: Final = re.compile(r"[^a-zA-Z0-9_-]")
+
+
+def replace_invalid_tool_use_id_chars(tool_use_id: str, invalid_chars: re.Pattern[str]) -> str:
+    return invalid_chars.sub("_", tool_use_id) or _TOOL_USE_ID_FALLBACK
+
+
+def sanitize_anthropic_tool_use_id(tool_use_id: str) -> str:
+    """Anthropic requires tool_use_id to match ^[a-zA-Z0-9_-]+$."""
+    return replace_invalid_tool_use_id_chars(tool_use_id, _ANTHROPIC_TOOL_USE_ID_INVALID_CHARS)
+
+
 _DECODED_JSON: Final = TypeAdapter(object)
 
 
@@ -3107,7 +3120,7 @@ def _attempt_json_repair(s: str) -> object | None:
 
 
 def parse_tool_call_arguments(
-    arguments: str | None,
+    arguments: str | Mapping[str, object] | None,
     tool_name: str | None = None,
     context: str | None = None,
 ) -> Any:
@@ -3120,7 +3133,7 @@ def parse_tool_call_arguments(
     callers are aware the arguments were not perfectly formed.
 
     Args:
-        arguments: The JSON string containing tool arguments, or None.
+        arguments: The JSON string containing tool arguments, an already-parsed mapping, or None.
         tool_name: Optional name of the tool (for error messages).
         context: Optional context string (e.g., "Anthropic Messages API").
 
@@ -3134,6 +3147,8 @@ def parse_tool_call_arguments(
     """
     import json
 
+    if isinstance(arguments, Mapping):
+        return dict(arguments)
     if not arguments or not arguments.strip():
         return {}
 
diff --git a/litellm/litellm_core_utils/prompt_templates/factory.py b/litellm/litellm_core_utils/prompt_templates/factory.py
index d6d753635f6..829cfe6bcc0 100644
--- a/litellm/litellm_core_utils/prompt_templates/factory.py
+++ b/litellm/litellm_core_utils/prompt_templates/factory.py
@@ -1,4 +1,5 @@
 import base64
+import codecs
 import copy
 import hashlib
 import itertools
@@ -8,7 +9,9 @@ import re
 import xml.etree.ElementTree as ET
 from collections.abc import Callable, Container, Iterable, Iterator, Mapping, Sequence
 from dataclasses import dataclass, replace
+from email.message import Message
 from enum import Enum
+from functools import cache, partial
 from types import MappingProxyType
 from typing import Annotated, Any, Final, TypeAlias, TypedDict, TypeVar, cast, overload
 
@@ -24,15 +27,18 @@ from litellm._uuid import uuid
 from litellm.constants import REDACTED_BY_LITELLM
 from litellm.litellm_core_utils.core_helpers import as_str_mapping, attribute_or_none
 from litellm.litellm_core_utils.prompt_templates.mid_conversation_system import (
+    answered_ids_by_index,
     anthropic_system_messages,
     find_anthropic_server_tool_result,
     is_anthropic_server_tool_use,
     is_anthropic_tool_search_use,
     message_field,
+    native_tool_use_id,
     parts_of,
     place_mid_conversation_system,
     split_leading_system_run,
     string_field,
+    tool_use_is_answered,
 )
 from litellm.litellm_core_utils.tool_fields import tools_without_hosted_mcp
 from litellm.litellm_core_utils.url_utils import async_safe_get, safe_get
@@ -75,7 +81,9 @@ from .common_utils import (
     is_unsignable_thinking_block,
     native_redacted_thinking_data,
     parse_tool_call_arguments,
+    replace_invalid_tool_use_id_chars,
     salvage_concatenated_tool_arguments,
+    sanitize_anthropic_tool_use_id,
 )
 from .image_handling import convert_url_to_base64
 
@@ -875,6 +883,18 @@ def convert_generic_image_chunk_to_openai_image_obj(
     return "data:{};{},{}".format(media_type, image_chunk["type"], image_chunk["data"])
 
 
+_CHARSET_AWARE_MEDIA_TYPE: Final = "text/plain"
+
+
+def _media_type_with_original_parameters(format_override: str, original_media_type: str) -> str:
+    if format_override.strip().lower() != _CHARSET_AWARE_MEDIA_TYPE:
+        return format_override
+    base_type, separator, parameters = original_media_type.partition(";")
+    if not separator or base_type.strip().lower() != format_override.strip().lower():
+        return format_override
+    return f"{format_override}{separator}{parameters}"
+
+
 def convert_to_anthropic_image_obj(openai_image_url: str, format: str | None) -> GenericImageParsingChunk:
     """
     Input:
@@ -893,7 +913,7 @@ def convert_to_anthropic_image_obj(openai_image_url: str, format: str | None) ->
         # Extract the media type and base64 data
         media_type, base64_data = openai_image_url.split("data:")[1].split(";base64,")
 
-        if format:
+        if isinstance(format, str) and format:
             media_type = format
         else:
             media_type = media_type.replace("\\/", "/")
@@ -935,8 +955,14 @@ def create_anthropic_image_param(
         # as these providers don't support URL sources for images
         if is_bedrock_invoke or image_url.startswith("http://"):
             base64_url: Final = convert_url_to_base64(url=image_url)
-            image_chunk = convert_to_anthropic_image_obj(openai_image_url=base64_url, format=format)
-            return _anthropic_content_element_factory(image_chunk)
+            return anthropic_content_element_factory(
+                convert_to_anthropic_image_obj(openai_image_url=base64_url, format=format)
+            )
+        elif isinstance(format, str) and format.partition(";")[0].strip().lower() == "application/pdf":
+            return AnthropicMessagesDocumentParam(
+                type="document",
+                source=AnthropicContentParamSourceUrl(type="url", url=image_url),
+            )
         else:
             # HTTPS URL - pass directly for regular Anthropic
             return AnthropicMessagesImageParam(
@@ -948,8 +974,9 @@ def create_anthropic_image_param(
             )
     else:
         # Convert to base64 for data URIs or other formats
-        image_chunk = convert_to_anthropic_image_obj(openai_image_url=image_url, format=format)
-        return _anthropic_content_element_factory(image_chunk)
+        return anthropic_content_element_factory(
+            convert_to_anthropic_image_obj(openai_image_url=image_url, format=format)
+        )
 
 
 # The following XML functions will be deprecated once JSON schema support is available on Bedrock and Vertex
@@ -1776,29 +1803,18 @@ def convert_to_gemini_tool_call_result(
     return _part
 
 
-_TOOL_USE_ID_FALLBACK: Final = "tool_use_id"
-_ANTHROPIC_TOOL_USE_ID_INVALID_CHARS: Final = re.compile(r"[^a-zA-Z0-9_-]")
 _BEDROCK_TOOL_USE_ID_INVALID_CHARS: Final = re.compile(r"[^a-zA-Z0-9_.:-]")
 _BEDROCK_TOOL_USE_ID_MAX_LEN: Final = 64
 _BEDROCK_TOOL_USE_ID_HASH_LEN: Final = 8
 
 
-def _replace_invalid_tool_use_id_chars(tool_use_id: str, invalid_chars: re.Pattern[str]) -> str:
-    return invalid_chars.sub("_", tool_use_id) or _TOOL_USE_ID_FALLBACK
-
-
-def sanitize_anthropic_tool_use_id(tool_use_id: str) -> str:
-    """Anthropic requires tool_use_id to match ^[a-zA-Z0-9_-]+$."""
-    return _replace_invalid_tool_use_id_chars(tool_use_id, _ANTHROPIC_TOOL_USE_ID_INVALID_CHARS)
-
-
 def _sanitize_bedrock_tool_use_id(tool_use_id: str) -> str:
     """
     Bedrock Converse requires toolUseId to match [a-zA-Z0-9_.:-]+ and be at most 64 chars.
     Ids that need rewriting get a short hash of the original appended so two ids that only
     differ in a replaced char or past the cut still map to distinct values.
     """
-    sanitized: Final = _replace_invalid_tool_use_id_chars(tool_use_id, _BEDROCK_TOOL_USE_ID_INVALID_CHARS)
+    sanitized: Final = replace_invalid_tool_use_id_chars(tool_use_id, _BEDROCK_TOOL_USE_ID_INVALID_CHARS)
     if sanitized == tool_use_id and len(sanitized) <= _BEDROCK_TOOL_USE_ID_MAX_LEN:
         return sanitized
     digest: Final = hashlib.sha256(tool_use_id.encode()).hexdigest()[:_BEDROCK_TOOL_USE_ID_HASH_LEN]
@@ -1808,15 +1824,124 @@ def _sanitize_bedrock_tool_use_id(tool_use_id: str) -> str:
 _ANTHROPIC_DOCUMENT_BASE64_MEDIA_TYPES: Final = {"application/pdf", "text/plain"}
 
 
-def _is_anthropic_document_data_uri(url: str) -> bool:
-    # Anthropic's base64 document source accepts only application/pdf and
-    # text/plain (see select_anthropic_content_block_type_for_file). Routing
-    # other mimes here would produce a document block the API rejects, so we
-    # leave them on the image code path.
+_PDF_SIGNATURE: Final = b"%PDF-"
+
+
+def _declared_media_type_for_data_uri(url: str, format_override: str | None) -> str | None:
+    if format_override and select_anthropic_content_block_type_for_file(format_override) != "container_upload":
+        return format_override
     match: Final = re.match(r"data:([^;,]+)", url)
-    if not match:
+    return match.group(1) if match else None
+
+
+def _base64_holds_a_pdf(data: str) -> bool:
+    try:
+        return base64.b64decode(data[:8]).startswith(_PDF_SIGNATURE)
+    except ValueError:
         return False
-    return match.group(1) in _ANTHROPIC_DOCUMENT_BASE64_MEDIA_TYPES
+
+
+def _data_uri_holds_a_pdf(url: str) -> bool:
+    _, _, payload = url.partition(",")
+    return _base64_holds_a_pdf(payload)
+
+
+def _data_uri_media_type(url: str) -> str:
+    header, separator, _ = url.partition(";base64,")
+    return header.removeprefix("data:") if separator and url.startswith("data:") else ""
+
+
+def anthropic_document_media_type_for_data_uri(url: str, format_override: str | None = None) -> str | None:
+    if not url.startswith("data:"):
+        return None
+    if _data_uri_holds_a_pdf(url):
+        return "application/pdf"
+    declared: Final = (_declared_media_type_for_data_uri(url, format_override) or "").lower()
+    return declared if declared in _ANTHROPIC_DOCUMENT_BASE64_MEDIA_TYPES else None
+
+
+_TEXT_ATTACHMENT_ENCODINGS: Final = frozenset(
+    codecs.lookup(label).name
+    for label in (
+        "utf-8",
+        "utf-16",
+        "utf-16-le",
+        "utf-16-be",
+        "ascii",
+        "latin-1",
+        *(f"iso8859-{part}" for part in (*range(2, 12), *range(13, 17))),
+        "tis-620",
+        *(f"cp{code_page}" for code_page in (866, 874, *range(1250, 1259))),
+        "koi8-r",
+        "koi8-u",
+        "mac-roman",
+        "mac-cyrillic",
+        "gb2312",
+        "gbk",
+        "gb18030",
+        "big5",
+        "big5hkscs",
+        "euc-jp",
+        "iso2022-jp",
+        "shift-jis",
+        "cp932",
+        "euc-kr",
+    )
+)
+
+
+def _text_attachment_encoding(charset: str) -> str:
+    encoding: Final = codecs.lookup(charset).name
+    if encoding not in _TEXT_ATTACHMENT_ENCODINGS:
+        raise LookupError(f"unsupported encoding: {charset}")
+    return encoding
+
+
+def _anthropic_text_document_source(
+    media_type_with_parameters: str, data: str
+) -> AnthropicContentParamSourceText | None:
+    media_type, _, _ = media_type_with_parameters.partition(";")
+    if media_type.strip().lower() != "text/plain":
+        return None
+    content_type_header: Final = Message()
+    content_type_header["content-type"] = media_type_with_parameters
+    charset: Final = content_type_header.get_content_charset("utf-8")
+    try:
+        text: Final = base64.b64decode(data).decode(_text_attachment_encoding(charset))
+    except (LookupError, UnicodeDecodeError) as decode_error:
+        raise litellm.BadRequestError(
+            message=f"Text attachment could not be read as {charset!r}: {decode_error}. "
+            "Send it as utf-8, or name its encoding (text/plain;charset=...) in the data URI "
+            "or in a file block's format.",
+            model=None,
+            llm_provider="anthropic",
+        ) from decode_error
+    return AnthropicContentParamSourceText(type="text", media_type="text/plain", data=text)
+
+
+def anthropic_document_block_from_data_uri(
+    url: str,
+    original_content_element: Mapping[str, object] | AllMessageValues,
+    media_type: str,
+) -> AnthropicMessagesDocumentParam:
+    synth_file_message: Final[ChatCompletionFileObject] = {
+        "type": "file",
+        "file": {"file_data": url, "format": media_type},
+    }
+    document_block: Final = anthropic_process_openai_file_message(synth_file_message)
+    return cast(
+        AnthropicMessagesDocumentParam,
+        add_cache_control_to_content(
+            anthropic_content_element=cast(AnthropicMessagesDocumentParam, document_block),
+            original_content_element=original_content_element,
+        ),
+    )
+
+
+def requires_inline_base64_media(model: str, llm_provider: str | None) -> bool:
+    if model.lower().startswith("invoke/"):
+        return True
+    return llm_provider is not None and llm_provider.startswith("vertex_ai")
 
 
 def convert_to_anthropic_tool_result(
@@ -1863,10 +1988,13 @@ def convert_to_anthropic_tool_result(
             | ToolReference
         ]
     ) = ""
-    if isinstance(message["content"], str):
-        anthropic_content = message["content"]
-    elif isinstance(message["content"], list):
-        content_list: Final = message["content"]
+    tool_content: Final = message.get("content")
+    if isinstance(tool_content, str):
+        anthropic_content = tool_content
+    elif isinstance(tool_content, (Mapping, int, float)):
+        anthropic_content = json.dumps(tool_content)
+    elif isinstance(tool_content, list):
+        content_list: Final = tool_content
         anthropic_content_list: list[
             AnthropicMessagesToolResultContent
             | AnthropicMessagesImageParam
@@ -1889,20 +2017,13 @@ def convert_to_anthropic_tool_result(
                 image_url_value = content["image_url"]
                 format = image_url_value.get("format") if isinstance(image_url_value, dict) else None
                 url_str = image_url_value.get("url") if isinstance(image_url_value, dict) else image_url_value
-                # Data URIs with non-image mime types (e.g. application/pdf) must
-                # translate to Anthropic document blocks, not image blocks —
-                # wrapping a PDF in `type: "image"` is rejected by the API.
-                if isinstance(url_str, str) and _is_anthropic_document_data_uri(url_str):
-                    synth_file_message: ChatCompletionFileObject = {
-                        "type": "file",
-                        "file": {"file_data": url_str},
-                    }
-                    _document_block = anthropic_process_openai_file_message(synth_file_message)
-                    _document_block = add_cache_control_to_content(
-                        anthropic_content_element=cast(AnthropicMessagesDocumentParam, _document_block),
-                        original_content_element=content,
+                if (
+                    isinstance(url_str, str)
+                    and (document_media_type := anthropic_document_media_type_for_data_uri(url_str, format)) is not None
+                ):
+                    anthropic_content_list.append(
+                        anthropic_document_block_from_data_uri(url_str, content, document_media_type)
                     )
-                    anthropic_content_list.append(cast(AnthropicMessagesDocumentParam, _document_block))
                 else:
                     _anthropic_image_param = create_anthropic_image_param(
                         image_url_value,
@@ -2129,6 +2250,7 @@ def convert_to_anthropic_tool_invoke(
     web_search_results: Sequence[object] | None = None,
     tool_results: Sequence[object] | None = None,
     answered_tool_ids: Container[str] = frozenset(),
+    drop_params: bool = False,
 ) -> list[_AnthropicToolInvokeItem]:
     """
     OpenAI tool invokes:
@@ -2183,10 +2305,8 @@ def convert_to_anthropic_tool_invoke(
             str,
             get_attribute_or_key(get_attribute_or_key(tool, "function"), "name"),
         )
-        tool_input = parse_tool_call_arguments(
-            get_attribute_or_key(get_attribute_or_key(tool, "function"), "arguments"),
-            tool_name=tool_name,
-            context="Anthropic tool invoke",
+        tool_input = _tool_call_input(
+            get_attribute_or_key(get_attribute_or_key(tool, "function"), "arguments"), tool_name, drop_params
         )
 
         server_tool_result = (
@@ -2244,7 +2364,7 @@ def add_cache_control_to_content(
     | AnthropicMessagesDocumentParam
     | AnthropicMessagesToolUseParam
     | ChatCompletionThinkingBlock,
-    original_content_element: dict | AllMessageValues | ChatCompletionFileObject,
+    original_content_element: Mapping[str, object] | AllMessageValues | ChatCompletionFileObject,
 ):
     cache_control_param: Final = original_content_element.get("cache_control")
     if cache_control_param is not None and isinstance(cache_control_param, dict):
@@ -2255,16 +2375,91 @@ def add_cache_control_to_content(
     return anthropic_content_element
 
 
-def _anthropic_content_element_factory(
+_TOOL_USE_INPUT: Final = TypeAdapter(dict[str, object])
+
+
+def _object_unless_dropped(value: object, drop_params: bool) -> object:
+    if not drop_params:
+        return value
+    try:
+        return _TOOL_USE_INPUT.validate_python(value)
+    except ValidationError:
+        return {}
+
+
+def _tool_call_input(arguments: str | Mapping[str, object] | None, tool_name: str, drop_params: bool) -> object:
+    try:
+        return _object_unless_dropped(
+            parse_tool_call_arguments(arguments, tool_name=tool_name, context="Anthropic tool invoke"), drop_params
+        )
+    except ValueError:
+        if drop_params:
+            return {}
+        raise
+
+
+def _tool_use_input_object(value: object, tool_name: str) -> dict[str, object]:
+    try:
+        return _TOOL_USE_INPUT.validate_python(value)
+    except ValidationError as error:
+        raise ValueError(
+            f"Tool input for tool '{tool_name}' (Anthropic assistant tool_use block) must be a JSON object, "
+            f"got {type(value).__name__}. Pass drop_params=True to send an empty object in its place"
+        ) from error
+
+
+def _parsed_native_tool_use_input(raw: object, tool_name: str) -> object:
+    if not isinstance(raw, str):
+        return raw
+    return parse_tool_call_arguments(
+        "{}" if raw == REDACTED_BY_LITELLM else raw,
+        tool_name=tool_name,
+        context="Anthropic assistant tool_use block",
+    )
+
+
+def _native_tool_use_input(raw: object, tool_name: str, drop_params: bool) -> dict[str, object]:
+    try:
+        return _tool_use_input_object(_parsed_native_tool_use_input(raw, tool_name), tool_name)
+    except ValueError:
+        if drop_params:
+            return {}
+        raise
+
+
+def _tool_call_ids(message: Mapping[str, object]) -> frozenset[str]:
+    return frozenset(native_tool_use_id(tool_call) for tool_call in parts_of(message.get("tool_calls")))
+
+
+def _anthropic_native_tool_use_block(
+    block: Mapping[str, object], tool_use_id: str, drop_params: bool
+) -> AnthropicMessagesToolUseParam:
+    tool_name: Final = str(block.get("name", ""))
+    tool_use_param: Final = AnthropicMessagesToolUseParam(
+        type="tool_use",
+        id=tool_use_id,
+        name=tool_name,
+        input=_native_tool_use_input(block.get("input"), tool_name, drop_params),
+    )
+    add_cache_control_to_content(
+        anthropic_content_element=tool_use_param,
+        original_content_element=dict(block),
+    )
+    return tool_use_param
+
+
+def anthropic_content_element_factory(
     image_chunk: GenericImageParsingChunk,
 ) -> AnthropicMessagesImageParam | AnthropicMessagesDocumentParam:
-    if image_chunk["media_type"] == "application/pdf":
+    if image_chunk["media_type"].partition(";")[0].strip().lower() == "application/pdf" or _base64_holds_a_pdf(
+        image_chunk["data"]
+    ):
         _anthropic_content_element: AnthropicMessagesDocumentParam | AnthropicMessagesImageParam = (
             AnthropicMessagesDocumentParam(
                 type="document",
                 source=AnthropicContentParamSource(
                     type="base64",
-                    media_type=image_chunk["media_type"],
+                    media_type="application/pdf",
                     data=image_chunk["data"],
                 ),
             )
@@ -2283,11 +2478,14 @@ def _anthropic_content_element_factory(
 
 
 def select_anthropic_content_block_type_for_file(
-    format: str,
+    format: object,
 ) -> Literal["document", "image", "container_upload"]:
-    if format == "application/pdf" or format == "text/plain":
+    if not isinstance(format, str):
+        return "container_upload"
+    media_type: Final = format.strip().lower()
+    if media_type == "application/pdf" or media_type == "text/plain":
         return "document"
-    elif format in ["image/jpeg", "image/png", "image/gif", "image/webp"]:
+    elif media_type in ["image/jpeg", "image/png", "image/gif", "image/webp"]:
         return "image"
     else:
         return "container_upload"
@@ -2327,11 +2525,27 @@ def anthropic_process_openai_file_message(
             openai_image_url=file_data,
             format=format,
         )
+        if _base64_holds_a_pdf(image_chunk["data"]):
+            return AnthropicMessagesDocumentParam(
+                type="document",
+                source=AnthropicContentParamSource(
+                    type="base64",
+                    media_type="application/pdf",
+                    data=image_chunk["data"],
+                ),
+            )
+        text_source: Final = _anthropic_text_document_source(
+            _media_type_with_original_parameters(image_chunk["media_type"], _data_uri_media_type(file_data)),
+            image_chunk["data"],
+        )
+        if text_source is not None:
+            return AnthropicMessagesDocumentParam(type="document", source=text_source)
+        media_type, _, _ = image_chunk["media_type"].partition(";")
         anthropic_document_param: Final = AnthropicMessagesDocumentParam(
             type="document",
             source=AnthropicContentParamSource(
                 type="base64",
-                media_type=image_chunk["media_type"],
+                media_type=media_type.strip().lower(),
                 data=image_chunk["data"],
             ),
         )
@@ -2404,13 +2618,14 @@ def _with_placeholder_text(block: object) -> object:
     return {**fields, "text": _EMPTY_TEXT_PLACEHOLDER}
 
 
-def _survives_assistant_conversion(block: object) -> bool:
+def _survives_assistant_conversion(block: object, answered: Callable[[], frozenset[str]]) -> bool:
     """Whether ``anthropic_messages_pt`` keeps this list-content block of an assistant turn.
 
     Mirrors the assistant converter: a ``thinking`` / ``redacted_thinking`` block is kept
-    unless it is unsignable (a signed block is kept even with empty text), and
-    ``server_tool_use`` and ``*_tool_result`` blocks pass through. A redacted block with
-    blank data is dropped under ``drop_params``, which is not known here, so it never counts.
+    unless it is unsignable (a signed block is kept even with empty text),
+    ``server_tool_use`` and ``*_tool_result`` blocks pass through, and a native ``tool_use``
+    is kept when the next turn answers it. A redacted block with blank data is dropped under
+    ``drop_params``, which is not known here, so it never counts.
     """
     fields: Final = _dict_block(block)
     if fields is None:
@@ -2420,6 +2635,8 @@ def _survives_assistant_conversion(block: object) -> bool:
     match fields:
         case {"type": "server_tool_use"}:
             return True
+        case {"type": "tool_use"}:
+            return tool_use_is_answered(native_tool_use_id(fields), answered())
         case {"type": str() as block_type}:
             return block_type.endswith("_tool_result")
         case _:
@@ -2441,12 +2658,16 @@ def _tool_call_survives_conversion(tool_call: object) -> bool:
             return True
 
 
-def _carries_non_text_content(message: AllMessageValues) -> bool:
+def _carries_non_text_content(message: AllMessageValues, answered: Callable[[], frozenset[str]]) -> bool:
     if any(_tool_call_survives_conversion(tool_call) for tool_call in parts_of(message_field(message, "tool_calls"))):
         return True
     content: Final = message_field(message, "content")
     blocks: Final = parts_of(content)
-    return isinstance(content, list) and any(_survives_assistant_conversion(block) for block in blocks)
+    return isinstance(content, list) and any(_survives_assistant_conversion(block, answered) for block in blocks)
+
+
+def _answered_at(answered_by_index: Callable[[], Mapping[int, frozenset[str]]], index: int) -> frozenset[str]:
+    return answered_by_index().get(index, frozenset())
 
 
 def _with_content(message: AllMessageValues, content: object, action: str) -> AllMessageValues:
@@ -2457,6 +2678,7 @@ def _with_content(message: AllMessageValues, content: object, action: str) -> Al
 
 def _sanitize_empty_text_content(
     message: AllMessageValues,
+    answered: Callable[[], frozenset[str]],
 ) -> AllMessageValues:
     """
     Case C: Sanitize empty text content
@@ -2464,8 +2686,8 @@ def _sanitize_empty_text_content(
     Anthropic rejects empty text blocks, so empty or whitespace-only text must never be
     forwarded verbatim. What replaces it depends on what else the turn carries.
 
-    Assistant turns that already carry substantive content (``tool_calls``, or non-text
-    blocks such as ``server_tool_use``) get the empty text dropped. Anthropic accepts an
+    Assistant turns that already carry substantive content (``tool_calls``, an answered
+    ``tool_use``, or other non-text blocks such as ``server_tool_use``) get the empty text dropped. Anthropic accepts an
     assistant turn whose content is just ``tool_use``, so there is nothing to substitute, and
     substituting anyway leaks a protocol diagnostic into the conversation as though the
     assistant had said it, which the model then echoes on later turns.
@@ -2480,7 +2702,9 @@ def _sanitize_empty_text_content(
         return message
 
     content: Final = message_field(message, "content")
-    drop_empty_text: Final = message_field(message, "role") == "assistant" and _carries_non_text_content(message)
+    drop_empty_text: Final = message_field(message, "role") == "assistant" and _carries_non_text_content(
+        message, answered
+    )
 
     if isinstance(content, str):
         if content.strip():
@@ -2641,8 +2865,13 @@ def _tool_call_ids_of_the_latest_assistant(
     if message.get("role") != "assistant":
         return latest_ids
     tool_calls: Final = message.get("tool_calls") or ()
+    native_tool_uses: Final = (
+        part for part in parts_of(message.get("content")) if message_field(part, "type") == "tool_use"
+    )
     return frozenset(
-        tool_call_id for tool_call_id in map(_tool_call_id, cast(Iterable[object], tool_calls)) if tool_call_id
+        tool_call_id
+        for tool_call_id in map(_tool_call_id, (*cast(Iterable[object], tool_calls), *native_tool_uses))
+        if tool_call_id
     )
 
 
@@ -2761,6 +2990,7 @@ def _pair_tool_calls_with_results(messages: Sequence[AllMessageValues]) -> tuple
     latest_assistant_tool_call_ids: Final = tuple(
         itertools.accumulate(messages, _tool_call_ids_of_the_latest_assistant, initial=frozenset[object]())
     )
+    answered_by_index: Final = cache(partial(answered_ids_by_index, messages))
     sanitized_messages: list[AllMessageValues] = []
     i = 0
 
@@ -2768,7 +2998,7 @@ def _pair_tool_calls_with_results(messages: Sequence[AllMessageValues]) -> tuple
         current_message = messages[i]
 
         # Case C: Sanitize empty text content
-        current_message = _sanitize_empty_text_content(current_message)
+        current_message = _sanitize_empty_text_content(current_message, partial(_answered_at, answered_by_index, i))
 
         # Case A: Check if assistant message has tool_calls without following tool results
         if current_message.get("role") == "assistant":
@@ -2978,6 +3208,7 @@ def anthropic_messages_pt(
     model: str,
     llm_provider: str,
     drop_params: bool = False,
+    force_base64: bool = False,
 ) -> _AnthropicMessageList:
     """
     format messages for anthropic
@@ -3003,7 +3234,11 @@ def anthropic_messages_pt(
     # request will always 400 otherwise. The richer tool-call sanitization
     # (Cases A/B/D in `sanitize_messages_for_tool_calling`) remains gated on
     # `modify_params` because it actually mutates conversation structure.
-    messages = [_sanitize_empty_text_content(m) for m in messages]
+    answered_by_assistant_index: Final = cache(partial(answered_ids_by_index, messages))
+    messages = [
+        _sanitize_empty_text_content(m, partial(_answered_at, answered_by_assistant_index, i))
+        for i, m in enumerate(messages)
+    ]
     replaced_server_tool_answers: Final = server_tool_answers_replaced_by_their_result(messages)
     client_answered_tool_ids: Final = _tool_call_ids_in_tool_messages(messages) - replaced_server_tool_answers
 
@@ -3022,11 +3257,7 @@ def anthropic_messages_pt(
         else:
             messages.append(DEFAULT_USER_CONTINUE_MESSAGE_TYPED)
 
-    # Bedrock invoke models have format: invoke/...
-    # Vertex AI Anthropic also doesn't support URL sources for images
-    is_bedrock_invoke = model.lower().startswith("invoke/")
-    is_vertex_ai = llm_provider.startswith("vertex_ai") if llm_provider else False
-    force_base64 = is_bedrock_invoke or is_vertex_ai
+    inline_base64_media: Final = force_base64 or requires_inline_base64_media(model, llm_provider)
 
     tool_result_later_in_turn: Final = _tool_result_later_in_turn(messages, replaced_server_tool_answers)
     msg_i = 0
@@ -3049,26 +3280,27 @@ def anthropic_messages_pt(
                     for m in user_block_content:
                         if m.get("type", "") == "image_url":
                             m = cast(ChatCompletionImageObject, m)
-                            format = m["image_url"].get("format") if isinstance(m["image_url"], dict) else None
-                            # Convert ChatCompletionImageUrlObject to dict if needed
                             image_url_value = m["image_url"]
+                            url_str = image_url_value if isinstance(image_url_value, str) else image_url_value["url"]
+                            format = image_url_value.get("format") if isinstance(image_url_value, dict) else None
+                            if (
+                                document_media_type := anthropic_document_media_type_for_data_uri(url_str, format)
+                            ) is not None:
+                                user_content.append(
+                                    anthropic_document_block_from_data_uri(url_str, dict(m), document_media_type)
+                                )
+                                continue
                             if isinstance(image_url_value, str):
                                 image_url_input: str | dict[str, object] = image_url_value
                             else:
-                                # ChatCompletionImageUrlObject or dict case - convert to dict
                                 image_url_input = {
                                     "url": image_url_value["url"],
                                     "format": image_url_value.get("format"),
                                 }
-                            # Bedrock invoke models have format: invoke/...
-                            # Vertex AI Anthropic also doesn't support URL sources for images
-                            is_bedrock_invoke = model.lower().startswith("invoke/")
-                            is_vertex_ai = llm_provider.startswith("vertex_ai") if llm_provider else False
-                            force_base64 = is_bedrock_invoke or is_vertex_ai
                             _anthropic_content_element = create_anthropic_image_param(
                                 image_url_input,
                                 format=format,
-                                is_bedrock_invoke=force_base64,
+                                is_bedrock_invoke=inline_base64_media,
                             )
                             _content_element = add_cache_control_to_content(
                                 anthropic_content_element=_anthropic_content_element,
@@ -3137,7 +3369,7 @@ def anthropic_messages_pt(
             ) and message_field(user_message_types_block, "tool_call_id") not in replaced_server_tool_answers:
                 # OpenAI's tool message content will always be a string
                 user_content.append(
-                    convert_to_anthropic_tool_result(user_message_types_block, force_base64=force_base64)
+                    convert_to_anthropic_tool_result(user_message_types_block, force_base64=inline_base64_media)
                 )
 
             msg_i += 1
@@ -3198,6 +3430,7 @@ def anthropic_messages_pt(
                     web_search_results=_provider_specific_fields.get("web_search_results"),
                     tool_results=_provider_specific_fields.get("tool_results"),
                     answered_tool_ids=client_answered_tool_ids,
+                    drop_params=drop_params,
                 )
                 if assistant_tool_calls is not None
                 else ()
@@ -3323,9 +3556,11 @@ def anthropic_messages_pt(
                 if not _content_is_list:  # IMPORTANT: ADD THIS FIRST, ELSE ANTHROPIC WILL RAISE AN ERROR
                     assistant_content.extend(replayed_thinking_blocks)
                 if _content_is_list and _content_list is not None:
+                    tool_call_ids = _tool_call_ids(assistant_content_block)
                     for m in _with_missing_thinking_blocks(_content_list, replayed_thinking_blocks):
                         if not isinstance(m, dict):
                             continue
+                        block_type: str = str(m.get("type", ""))
                         # handle thinking blocks
                         if (thinking_block := _as_thinking_block(m)) is not None:
                             assistant_content.extend(
@@ -3337,7 +3572,7 @@ def anthropic_messages_pt(
                         text_block = cast(str, m.get("text", ""))
                         # handle text
                         if (
-                            m.get("type", "") == "text" and len(text_block) > 0
+                            block_type == "text" and len(text_block) > 0
                         ):  # don't pass empty text blocks. anthropic api raises errors.
                             anthropic_message = AnthropicMessagesTextParam(type="text", text=text_block)
                             _cached_message = add_cache_control_to_content(
@@ -3348,8 +3583,20 @@ def anthropic_messages_pt(
                             assistant_content.append(cast(AnthropicMessagesTextParam, _cached_message))
                         # handle server_tool_use blocks (tool search, web search, etc.)
                         # Pass through as-is since these are Anthropic-native content types
-                        elif m.get("type", "") == "server_tool_use" or m.get("type", "").endswith("_tool_result"):
+                        elif block_type == "server_tool_use" or block_type.endswith("_tool_result"):
                             assistant_content.append(m)
+                        elif block_type == "tool_use":
+                            tool_use_id = native_tool_use_id(m)
+                            if (
+                                tool_use_id in unique_tool_ids
+                                or tool_use_id in tool_call_ids
+                                or not tool_use_is_answered(
+                                    tool_use_id, answered_by_assistant_index().get(msg_i, frozenset())
+                                )
+                            ):
+                                continue
+                            unique_tool_ids.add(tool_use_id)
+                            assistant_content.append(_anthropic_native_tool_use_block(m, tool_use_id, drop_params))
                 elif (
                     "content" in assistant_content_block
                     and isinstance(assistant_content_block["content"], str)
@@ -3978,8 +4225,6 @@ def stringify_json_tool_call_content(messages: list) -> list:
 
 ###### AMAZON BEDROCK #######
 
-from email.message import Message
-
 import httpx
 
 from litellm.types.llms.bedrock import (
diff --git a/litellm/litellm_core_utils/prompt_templates/mid_conversation_system.py b/litellm/litellm_core_utils/prompt_templates/mid_conversation_system.py
index ec6de4e206d..1d6d4276ad2 100644
--- a/litellm/litellm_core_utils/prompt_templates/mid_conversation_system.py
+++ b/litellm/litellm_core_utils/prompt_templates/mid_conversation_system.py
@@ -49,7 +49,7 @@ from litellm.types.llms.openai import (
     ChatCompletionUserMessage,
 )
 
-from .common_utils import has_blank_redacted_data, is_unsignable_thinking_block
+from .common_utils import has_blank_redacted_data, is_unsignable_thinking_block, sanitize_anthropic_tool_use_id
 
 CONVERTED_SYSTEM_NOTE: Final = (
     "Operator note (not from the user): the following was originally a mid-conversation system-role reminder."
@@ -277,11 +277,25 @@ def _thinking_block_renders(block: object) -> bool:
     )
 
 
-def _assistant_part_renders(part: object) -> bool:
-    """A text part always renders: the converter pads empty text with a placeholder."""
+def native_tool_use_id(block: object) -> str:
+    raw_id: Final = message_field(block, "id")
+    return sanitize_anthropic_tool_use_id(raw_id if isinstance(raw_id, str) else "")
+
+
+def tool_use_is_answered(tool_use_id: str, answered: frozenset[str]) -> bool:
+    return tool_use_id in answered
+
+
+def _assistant_part_renders(part: object, answered: frozenset[str]) -> bool:
+    """A text part always renders: the converter pads empty text with a placeholder.
+
+    A native ``tool_use`` renders only when the next turn answers it, since the converter drops an orphan.
+    """
     part_type: Final = message_field(part, "type")
     if part_type in _THINKING_BLOCK_TYPES:
         return _thinking_block_renders(part)
+    if part_type == "tool_use":
+        return tool_use_is_answered(native_tool_use_id(part), answered)
     return part_type in _RENDERED_ASSISTANT_PART_TYPES or (
         isinstance(part_type, str) and part_type.endswith("_tool_result")
     )
@@ -317,6 +331,7 @@ def _tool_result_ids(answers: Iterable[object]) -> Iterator[str]:
     for message in answers:
         if isinstance(tool_call_id := message_field(message, "tool_call_id"), str) and tool_call_id:
             yield tool_call_id
+            yield sanitize_anthropic_tool_use_id(tool_call_id)
 
 
 def answered_tool_call_ids(messages: Sequence[object], assistant_index: int) -> frozenset[str]:
@@ -343,7 +358,7 @@ def _answered_by_assistant_index(
     return ((index, answered) for index, _ in groups[group_index][1])
 
 
-def _answered_ids_by_index(messages: Sequence[object]) -> Mapping[int, frozenset[str]]:
+def answered_ids_by_index(messages: Sequence[object]) -> Mapping[int, frozenset[str]]:
     """``answered_tool_call_ids`` for every assistant message, computed in one pass over the messages."""
     groups: Final = tuple(
         (role_group, tuple(group))
@@ -407,7 +422,7 @@ def _assistant_renders(message: object, answered: frozenset[str]) -> bool:
         return True
     parts: Final = parts_of(content)
     return (
-        any(_assistant_part_renders(part) for part in parts)
+        any(_assistant_part_renders(part, answered) for part in parts)
         or _separate_thinking_blocks_render(message)
         or _tool_calls_render(message, answered)
         or bool(message_field(message, "function_call"))
@@ -438,7 +453,7 @@ def _renders(message: object, answered: frozenset[str]) -> bool:
 
 
 def _rendered_indices(messages: Sequence[object]) -> frozenset[int]:
-    answered: Final = _answered_ids_by_index(messages)
+    answered: Final = answered_ids_by_index(messages)
     return frozenset(index for index, message in enumerate(messages) if _renders(message, answered.get(index, _NO_IDS)))
 
 
diff --git a/litellm/llms/anthropic/chat/transformation.py b/litellm/llms/anthropic/chat/transformation.py
index 2e908e66626..d149cc5c89c 100644
--- a/litellm/llms/anthropic/chat/transformation.py
+++ b/litellm/llms/anthropic/chat/transformation.py
@@ -2481,6 +2481,8 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
                 llm_provider=self._resolved_provider,
                 drop_params=drop_params,
             )
+        except litellm.BadRequestError as e:
+            raise non_string_message_field_error(messages, e) or AnthropicError(status_code=400, message=str(e))
         except Exception as e:
             conversion_field_error: Final = non_string_message_field_error(messages, e)
             raise conversion_field_error or AnthropicError(
diff --git a/litellm/llms/anthropic/count_tokens/handler.py b/litellm/llms/anthropic/count_tokens/handler.py
index 7a7d1d776d3..166896d52e4 100644
--- a/litellm/llms/anthropic/count_tokens/handler.py
+++ b/litellm/llms/anthropic/count_tokens/handler.py
@@ -118,6 +118,8 @@ class AnthropicCountTokensHandler(AnthropicCountTokensConfig):
         except AnthropicError:
             # Re-raise Anthropic exceptions as-is
             raise
+        except litellm.BadRequestError:
+            raise
         except httpx.HTTPStatusError as e:
             # HTTP errors - preserve the actual status code
             verbose_logger.error("HTTP error in CountTokens handler: %s", e)
diff --git a/litellm/llms/anthropic/count_tokens/token_counter.py b/litellm/llms/anthropic/count_tokens/token_counter.py
index 99b1cd7f241..ddf5e797e20 100644
--- a/litellm/llms/anthropic/count_tokens/token_counter.py
+++ b/litellm/llms/anthropic/count_tokens/token_counter.py
@@ -144,6 +144,17 @@ class AnthropicTokenCounter(BaseTokenCounter):
                     tokenizer_type="anthropic_api",
                     original_response=result,
                 )
+        except litellm.BadRequestError as e:
+            return TokenCountResponse(
+                total_tokens=0,
+                request_model=request_model,
+                model_used=model_to_use,
+                tokenizer_type="anthropic_api",
+                error=True,
+                error_message=e.message,
+                status_code=400,
+                rejected_before_provider_call=True,
+            )
         except (AnthropicError, AuthenticationError) as e:
             verbose_logger.warning("Anthropic CountTokens error: status=%s, message=%s", e.status_code, e.message)
             return TokenCountResponse(
diff --git a/litellm/llms/anthropic/count_tokens/transformation.py b/litellm/llms/anthropic/count_tokens/transformation.py
index 1c8f0c206cd..8d61287eeb8 100644
--- a/litellm/llms/anthropic/count_tokens/transformation.py
+++ b/litellm/llms/anthropic/count_tokens/transformation.py
@@ -49,16 +49,25 @@ _PLAIN_MESSAGE_KEYS: Final = frozenset({"role", "content"})
 def _count_image(block: JsonValue) -> JsonValue:
     if not isinstance(block, dict) or block.get("type") != "image_url":
         return block
-    from litellm.litellm_core_utils.prompt_templates.factory import convert_to_anthropic_image_obj
+    from litellm.litellm_core_utils.prompt_templates.factory import (
+        anthropic_content_element_factory,
+        anthropic_document_block_from_data_uri,
+        anthropic_document_media_type_for_data_uri,
+        convert_to_anthropic_image_obj,
+    )
 
     image_block: Final = _IMAGE_BLOCK.validate_python(block)
     image_url: Final = image_block["image_url"]
-    source: Final = convert_to_anthropic_image_obj(
-        openai_image_url=image_url if isinstance(image_url, str) else image_url["url"],
-        format=image_url.get("format") if isinstance(image_url, dict) else None,
-    )
-    image: Final = _COUNT_REQUEST.validate_python({"type": "image", "source": source})
-    return {**{key: value for key, value in block.items() if key not in {"type", "image_url"}}, **image}
+    url: Final = image_url if isinstance(image_url, str) else image_url["url"]
+    format_override: Final = image_url.get("format") if isinstance(image_url, dict) else None
+    other_fields: Final = {key: value for key, value in block.items() if key not in {"type", "image_url"}}
+    document_media_type: Final = anthropic_document_media_type_for_data_uri(url, format_override)
+    if document_media_type is not None:
+        document: Final = anthropic_document_block_from_data_uri(url, image_block, document_media_type)
+        return {**other_fields, **_COUNT_REQUEST.validate_python(document)}
+    source: Final = convert_to_anthropic_image_obj(openai_image_url=url, format=format_override)
+    media_block: Final = anthropic_content_element_factory(source)
+    return {**other_fields, **_COUNT_REQUEST.validate_python(media_block)}
 
 
 def _count_block(block: JsonValue) -> JsonValue:
diff --git a/litellm/llms/azure_ai/anthropic/count_tokens/handler.py b/litellm/llms/azure_ai/anthropic/count_tokens/handler.py
index 97ee44bd3bb..a0c4d767692 100644
--- a/litellm/llms/azure_ai/anthropic/count_tokens/handler.py
+++ b/litellm/llms/azure_ai/anthropic/count_tokens/handler.py
@@ -135,6 +135,8 @@ class AzureAIAnthropicCountTokensHandler(AzureAIAnthropicCountTokensConfig):
         except AnthropicError:
             # Re-raise Anthropic exceptions as-is
             raise
+        except litellm.BadRequestError:
+            raise
         except httpx.HTTPStatusError as e:
             # HTTP errors - preserve the actual status code
             verbose_logger.error("HTTP error in CountTokens handler: %s", e)
diff --git a/litellm/llms/azure_ai/anthropic/count_tokens/token_counter.py b/litellm/llms/azure_ai/anthropic/count_tokens/token_counter.py
index 14f7d4bfd2b..58063fcdc34 100644
--- a/litellm/llms/azure_ai/anthropic/count_tokens/token_counter.py
+++ b/litellm/llms/azure_ai/anthropic/count_tokens/token_counter.py
@@ -148,6 +148,17 @@ class AzureAIAnthropicTokenCounter(BaseTokenCounter):
                         "original_response": result,
                     }
                 )
+        except litellm.BadRequestError as e:
+            return TokenCountResponse(
+                total_tokens=0,
+                request_model=request_model,
+                model_used=model_to_use,
+                tokenizer_type="azure_ai_anthropic_api",
+                error=True,
+                error_message=e.message,
+                status_code=400,
+                rejected_before_provider_call=True,
+            )
         except AnthropicError as e:
             verbose_logger.warning(
                 "Azure AI Anthropic CountTokens API error: status=%s, message=%s", e.status_code, e.message
diff --git a/litellm/llms/bedrock/count_tokens/bedrock_token_counter.py b/litellm/llms/bedrock/count_tokens/bedrock_token_counter.py
index dec099f37c0..e22f2df4f03 100644
--- a/litellm/llms/bedrock/count_tokens/bedrock_token_counter.py
+++ b/litellm/llms/bedrock/count_tokens/bedrock_token_counter.py
@@ -54,6 +54,7 @@ class CountTokensFailure:
     status_code: int
     message: str
     tokenizer_type: str
+    rejected_before_provider_call: bool = False
 
 
 CountTokensOutcome = CountedTokens | CountTokensFailure
@@ -162,6 +163,10 @@ class BedrockTokenCounter(BaseTokenCounter):
                 client=self._client,
             )
             reply: Final = _CountTokensReply.model_validate(result)
+        except litellm.BadRequestError as e:
+            return CountTokensFailure(
+                status_code=400, message=e.message, tokenizer_type=tokenizer_type, rejected_before_provider_call=True
+            )
         except BedrockError as e:
             verbose_logger.debug(
                 "%s CountTokens API error: status=%s, message=%s", tokenizer_type, e.status_code, e.message
@@ -268,6 +273,7 @@ class BedrockTokenCounter(BaseTokenCounter):
                     error=True,
                     error_message=outcome.message,
                     status_code=outcome.status_code,
+                    rejected_before_provider_call=outcome.rejected_before_provider_call,
                 )
             case _:
                 assert_never(outcome)
diff --git a/litellm/llms/bedrock/count_tokens/mantle_handler.py b/litellm/llms/bedrock/count_tokens/mantle_handler.py
index 5e5c5516b94..2a6d4d53cb2 100644
--- a/litellm/llms/bedrock/count_tokens/mantle_handler.py
+++ b/litellm/llms/bedrock/count_tokens/mantle_handler.py
@@ -106,7 +106,7 @@ class BedrockMantleCountTokensHandler(BaseAWSLLM):
                     response=response,
                 )
             return _COUNT_RESPONSE.validate_json(response.content)
-        except BedrockError:
+        except (BedrockError, litellm.BadRequestError):
             raise
         except httpx.HTTPStatusError as e:
             raise BedrockError(
diff --git a/litellm/llms/snowflake/chat/transformation.py b/litellm/llms/snowflake/chat/transformation.py
index 928dcc3bc52..a300bd9d161 100644
--- a/litellm/llms/snowflake/chat/transformation.py
+++ b/litellm/llms/snowflake/chat/transformation.py
@@ -8,28 +8,24 @@ Routes to native Cortex REST API endpoints based on model:
 Ref: https://docs.snowflake.com/en/user-guide/snowflake-cortex/cortex-rest-api
 """
 
-import copy
-import json
-import re
 from collections.abc import Mapping, Sequence
+from itertools import chain
 from typing import TYPE_CHECKING, Any, Final, Protocol, TypedDict
 
 import httpx
 from typing_extensions import ReadOnly
 
-from litellm.litellm_core_utils.core_helpers import as_str_mapping
-from litellm.litellm_core_utils.prompt_templates.factory import (
-    anthropic_process_openai_file_message,
-    convert_to_anthropic_tool_result,
-    create_anthropic_image_param,
-    select_anthropic_content_block_type_for_file,
-)
+import litellm
+from litellm.exceptions import BadRequestError
+from litellm.litellm_core_utils.prompt_templates.factory import anthropic_messages_pt
 from litellm.litellm_core_utils.prompt_templates.image_handling import async_inline_remote_media
+from litellm.litellm_core_utils.prompt_templates.mid_conversation_system import message_field, parts_of
 from litellm.litellm_core_utils.url_utils import join_api_base
 from litellm.llms.anthropic.chat.handler import ModelResponseIterator as AnthropicStreamParser
 from litellm.llms.anthropic.chat.transformation import AnthropicConfig
 from litellm.llms.anthropic.common_utils import normalize_cache_control_in_anthropic_payload
-from litellm.types.llms.openai import AllMessageValues, ChatCompletionToolCallChunk, ChatCompletionToolMessage
+from litellm.types.llms.anthropic import AllAnthropicPassThroughMessageValues, AnthropicSystemMessageContent
+from litellm.types.llms.openai import AllMessageValues, ChatCompletionToolCallChunk
 from litellm.types.utils import (
     Choices,
     GenericStreamingChunk,
@@ -40,7 +36,7 @@ from litellm.types.utils import (
 
 from ...base_llm.base_model_iterator import BaseModelResponseIterator
 from ...openai_like.chat.transformation import OpenAIGPTConfig
-from ..utils import SnowflakeBaseConfig
+from ..utils import SnowflakeBaseConfig, SnowflakeException
 
 if TYPE_CHECKING:
     from litellm.litellm_core_utils.litellm_logging import Logging as _LiteLLMLoggingObj
@@ -104,115 +100,21 @@ def is_snowflake_claude_model(model: str) -> bool:
     return any(name.startswith(p) for p in _CLAUDE_MODEL_PREFIXES)
 
 
-def _convert_image_url_to_anthropic(block: Mapping[str, object]) -> object:
-    """One OpenAI ``image_url`` block in the native shape Cortex accepts.
-
-    Cortex documents base64 sources only, so remote URLs are inlined the way every
-    other base64-only Anthropic dialect (Bedrock invoke, Vertex) inlines them, and
-    pdf/text data URIs become document blocks rather than malformed image blocks.
-    """
-    image_url: Final = block.get("image_url")
-    url: Final = image_url if isinstance(image_url, str) else _str_field(image_url, "url")
-    if not url:
-        return block
-
-    converted: Final = (
-        anthropic_process_openai_file_message({"type": "file", "file": {"file_data": url}})
-        if select_anthropic_content_block_type_for_file(_data_uri_media_type(url)) == "document"
-        else create_anthropic_image_param(
-            image_url if isinstance(image_url, dict) else url,
-            format=_str_field(image_url, "format"),
-            is_bedrock_invoke=True,
-        )
-    )
-    return _with_cache_control(converted, block)
+_CORTEX_CLAUDE_USER_PART_TYPES: Final = frozenset({"text", "image_url", "document", "file"})
 
 
-def _convert_file_to_anthropic(block: Mapping[str, object]) -> object:
-    file_data: Final = _str_field(block.get("file"), "file_data")
-    if not file_data:
-        return block
-    return _with_cache_control(
-        anthropic_process_openai_file_message({"type": "file", "file": {"file_data": file_data}}), block
-    )
+def _user_parts(message: AllMessageValues) -> tuple[object, ...]:
+    return parts_of(message.get("content")) if message["role"] == "user" else ()
 
 
-def _with_cache_control(converted: Mapping[str, object], block: Mapping[str, object]) -> Mapping[str, object]:
-    cache_control: Final = block.get("cache_control")
-    if cache_control is None:
-        return converted
-    return {**converted, "cache_control": cache_control}
+def _part_type(part: object) -> str:
+    part_type: Final = message_field(part, "type")
+    return f"untyped {type(part).__name__}" if part_type is None else str(part_type)
 
 
-def _str_field(container: object, key: str) -> str | None:
-    value: Final = container.get(key) if isinstance(container, dict) else None
-    return value if isinstance(value, str) else None
-
-
-def _data_uri_media_type(url: str) -> str:
-    match: Final = re.match(r"data:([^;,]+)", url)
-    return match.group(1) if match else ""
-
-
-def _convert_media_block_to_anthropic(block: object) -> object:
-    mapping: Final = as_str_mapping(block)
-    if mapping is None:
-        return block
-    match mapping.get("type"):
-        case "image_url":
-            return _convert_image_url_to_anthropic(mapping)
-        case "file":
-            return _convert_file_to_anthropic(mapping)
-        case _:
-            return block
-
-
-def _convert_media_blocks_to_anthropic(content: object) -> object:
-    if not isinstance(content, list):
-        return content
-    return [_convert_media_block_to_anthropic(block) for block in content]
-
-
-def _convert_tool_result_to_anthropic(
-    content: object, tool_call_id: str, cache_control: object
-) -> Mapping[str, object]:
-    """The Anthropic ``tool_result`` block for one OpenAI tool message.
-
-    Delegating to the shared converter keeps image, document and per-block cache
-    breakpoints identical to every other Anthropic dialect; only the plain-string
-    and non-list shapes it does not model are handled here.
-    """
-    if not isinstance(content, list):
-        plain: Final[dict[str, object]] = {  # mutable-ok: JSON wire block
-            "type": "tool_result",
-            "tool_use_id": tool_call_id,
-            "content": content if isinstance(content, str) else json.dumps(content),
-        }
-        return {**plain, "cache_control": cache_control} if cache_control is not None else plain
-    converted: Final = convert_to_anthropic_tool_result(
-        ChatCompletionToolMessage(role="tool", tool_call_id=tool_call_id, content=content),
-        force_base64=True,
-    )
-    if cache_control is None:
-        return converted
-    return {**converted, "cache_control": cache_control}
-
-
-def _signed_thinking_blocks(msg: object) -> list[dict[str, object]]:  # mutable-ok: JSON wire blocks
-    """The assistant turn's thinking blocks that can legally be echoed back.
-
-    Only signed blocks round-trip: Cortex rejects a thinking block whose signature is
-    missing, which is what an unsigned block from a non-thinking turn would produce.
-    """
-    blocks: Final = msg.get("thinking_blocks") if isinstance(msg, dict) else getattr(msg, "thinking_blocks", None)
-    if not isinstance(blocks, list):
-        return []
-    mappings: Final = tuple(filter(None, map(as_str_mapping, blocks)))
-    return [
-        {key: value for key, value in block.items() if key != "index"}
-        for block in mappings
-        if block.get("signature") or block.get("type") == "redacted_thinking"
-    ]
+def _untranslatable_user_part_types(messages: Sequence[AllMessageValues]) -> frozenset[str]:
+    part_types: Final = frozenset(map(_part_type, chain.from_iterable(map(_user_parts, messages))))
+    return part_types - _CORTEX_CLAUDE_USER_PART_TYPES
 
 
 def _clean_input_schema(schema: object) -> object:
@@ -319,105 +221,34 @@ class SnowflakeConfig(SnowflakeBaseConfig, OpenAIGPTConfig):
                 )
         return anthropic_tools
 
-    def _extract_system_and_messages(self, messages: list[AllMessageValues]) -> tuple[list[dict] | None, list[dict]]:
-        """
-        Split messages into system prompt and conversation turns for Anthropic format.
-
-        - system messages → collected and joined (preserves guardrail prompts)
-        - assistant messages with tool_calls → tool_use content blocks
-        - tool role messages → user role with tool_result content blocks
-        """
-        system_parts: Final[list[dict]] = []  # mutable-ok: JSON wire messages
-        conversation: Final[list[dict]] = []  # mutable-ok: JSON wire messages
-
-        for msg in messages:
-            if isinstance(msg, dict):
-                role = msg.get("role", "")
-                content: object = msg.get("content", "")
-                msg_cache_control: object = msg.get("cache_control")
-            else:
-                role = getattr(msg, "role", "")
-                content = getattr(msg, "content", "")
-                msg_cache_control = getattr(msg, "cache_control", None)
-
-            if role == "system":
-                if isinstance(content, str) and content:
-                    system_parts.append({"type": "text", "text": content})
-                elif isinstance(content, list):
-                    system_parts.extend(
-                        {
-                            "type": "text",
-                            "text": block.get("text", ""),
-                            **({"cache_control": block["cache_control"]} if "cache_control" in block else {}),
-                        }
-                        for block in content
-                        if isinstance(block, Mapping) and block.get("type") == "text"
-                    )
-            elif role == "assistant":
-                tool_calls = msg.get("tool_calls") if isinstance(msg, dict) else getattr(msg, "tool_calls", None)
-                thinking_blocks = _signed_thinking_blocks(msg)
-                if tool_calls:
-                    content_blocks: list[dict[str, object]] = list(thinking_blocks)  # mutable-ok: JSON wire blocks
-                    if content:
-                        content_blocks.append({"type": "text", "text": content})
-                    for tc in tool_calls:
-                        func = tc.get("function", {}) if isinstance(tc, dict) else getattr(tc, "function", {})
-                        tc_id = tc.get("id", "") if isinstance(tc, dict) else getattr(tc, "id", "")
-                        func_name = func.get("name", "") if isinstance(func, dict) else getattr(func, "name", "")
-                        func_args = (
-                            func.get("arguments", "{}") if isinstance(func, dict) else getattr(func, "arguments", "{}")
-                        )
-                        try:
-                            input_data = json.loads(func_args) if isinstance(func_args, str) else func_args
-                        except (json.JSONDecodeError, TypeError):
-                            input_data = {}
-                        content_blocks.append(
-                            {
-                                "type": "tool_use",
-                                "id": tc_id,
-                                "name": func_name,
-                                "input": input_data,
-                            }
-                        )
-                    conversation.append({"role": "assistant", "content": content_blocks})
-                elif thinking_blocks:
-                    thinking_content = (
-                        [
-                            *thinking_blocks,
-                            *copy.deepcopy(content),
-                        ]
-                        if isinstance(content, list)
-                        else [*thinking_blocks, *([{"type": "text", "text": content}] if content else [])]
-                    )
-                    conversation.append({"role": "assistant", "content": thinking_content})
-                else:
-                    conversation.append({"role": "assistant", "content": content})
-            elif role == "tool":
-                tool_call_id_value = (
-                    msg.get("tool_call_id", "") if isinstance(msg, dict) else getattr(msg, "tool_call_id", "")
-                )
-                tool_call_id = tool_call_id_value if isinstance(tool_call_id_value, str) else ""
-                tool_result_block = _convert_tool_result_to_anthropic(content, tool_call_id, msg_cache_control)
-                if (
-                    conversation
-                    and conversation[-1]["role"] == "user"
-                    and isinstance(conversation[-1]["content"], list)
-                    and conversation[-1]["content"]
-                    and conversation[-1]["content"][0].get("type") == "tool_result"
-                ):
-                    conversation[-1]["content"].append(tool_result_block)
-                else:
-                    conversation.append({"role": "user", "content": [tool_result_block]})
-            else:
-                conversation.append(
-                    {
-                        "role": role,
-                        "content": _convert_media_blocks_to_anthropic(content),
-                    }
-                )
-
-        system: Final[list[dict] | None] = system_parts if system_parts else None  # mutable-ok: JSON wire messages
-        return system, conversation
+    def _extract_system_and_messages(
+        self, model: str, messages: list[AllMessageValues], drop_params: bool
+    ) -> tuple[list[AnthropicSystemMessageContent] | None, list[AllAnthropicPassThroughMessageValues]]:
+        """Cortex's /messages endpoint speaks Anthropic's dialect, so the shared translators own the shape."""
+        conversation_messages: Final = list(messages)
+        untranslatable: Final = _untranslatable_user_part_types(conversation_messages)
+        if untranslatable and not drop_params:
+            raise SnowflakeException(
+                status_code=400,
+                message=f"Snowflake Cortex Claude cannot take {', '.join(sorted(untranslatable))} parts in a user "
+                "message. Remove them, or pass drop_params=True to drop them",
+            )
+        system: Final = [
+            part
+            for part in AnthropicConfig().translate_system_message(messages=conversation_messages)
+            if part.get("type") == "text"
+        ]
+        try:
+            conversation: Final = anthropic_messages_pt(
+                messages=conversation_messages,
+                model=model,
+                llm_provider="snowflake",
+                drop_params=drop_params,
+                force_base64=True,
+            )
+        except (AttributeError, LookupError, TypeError, ValueError, BadRequestError) as e:
+            raise SnowflakeException(status_code=400, message=str(e)) from e
+        return (system or None), conversation
 
     def transform_request(
         self,
@@ -431,7 +262,8 @@ class SnowflakeConfig(SnowflakeBaseConfig, OpenAIGPTConfig):
         extra_body: Final = optional_params.pop("extra_body", {})
 
         if is_snowflake_claude_model(model):
-            return self._transform_request_anthropic(model, messages, optional_params, stream, extra_body)
+            drop_params: Final = litellm.drop_params is True or litellm_params.get("drop_params") is True
+            return self._transform_request_anthropic(model, messages, optional_params, stream, extra_body, drop_params)
         return self._transform_request_openai(model, messages, optional_params, stream, extra_body)
 
     @property
@@ -506,10 +338,11 @@ class SnowflakeConfig(SnowflakeBaseConfig, OpenAIGPTConfig):
         optional_params: dict,
         stream: bool,
         extra_body: dict,
+        drop_params: bool,
     ) -> dict:
         """Anthropic Messages format for /messages endpoint."""
         passthrough_system: Final = optional_params.pop("system", None)
-        extracted_system, conversation = self._extract_system_and_messages(messages)
+        extracted_system, conversation = self._extract_system_and_messages(model, messages, drop_params)
         system: Final = passthrough_system if passthrough_system is not None else extracted_system
 
         if "tools" in optional_params:
diff --git a/tests/integration/providers/test_responses_bridge_message_cache_control_wire.py b/tests/integration/providers/test_responses_bridge_message_cache_control_wire.py
index 4b25275285e..1d3551fe549 100644
--- a/tests/integration/providers/test_responses_bridge_message_cache_control_wire.py
+++ b/tests/integration/providers/test_responses_bridge_message_cache_control_wire.py
@@ -962,10 +962,10 @@ def _shaped_requests(model: str, shape: str) -> tuple[dict[str, JsonValue], dict
         pytest.param(f"openrouter/anthropic/{ANTHROPIC_MODEL}", "system", True, id="openrouter-claude"),
         pytest.param("openrouter/google/gemini-3.8-flash", "system", True, id="openrouter-gemini"),
         pytest.param("snowflake/claude-4-sonnet", "tool", True, id="snowflake-claude-tool-output"),
+        pytest.param("snowflake/claude-4-sonnet", "system", True, id="snowflake-claude-string-system"),
         pytest.param("vertex-claude", "system", True, id="vertex-claude"),
         pytest.param("sap-claude", "system", True, id="sap-claude"),
         pytest.param("anthropic/my-gateway-model", "system", True, id="anthropic-non-claude-name"),
-        pytest.param("snowflake/claude-4-sonnet", "system", False, id="snowflake-claude-string-system"),
         pytest.param("openrouter/openai/gpt-5.4", "system", False, id="openrouter-gpt"),
         pytest.param("snowflake/llama3.1-70b", "system", False, id="snowflake-llama"),
         pytest.param("snowflake/llama-claude-distill", "system", False, id="snowflake-claude-inside-the-name"),
diff --git a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
index 146bb08a4fd..ae031367823 100644
--- a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
+++ b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_common_utils.py
@@ -5,6 +5,7 @@ import json
 import os
 import sys
 from collections.abc import Mapping
+from types import MappingProxyType
 from typing import Final, cast
 
 import pytest
@@ -2561,6 +2562,23 @@ def test_schema_size_counts_every_written_object_once(schema, properties, branch
     assert schema_grammar_branch_count(schema) == branches
 
 
+@pytest.mark.parametrize(
+    "arguments",
+    [{"already": "parsed"}, MappingProxyType({"already": "parsed"})],
+    ids=["dict", "mapping_proxy"],
+)
+def test_parse_tool_call_arguments_returns_already_parsed_mapping(arguments):
+    parsed = parse_tool_call_arguments(arguments, tool_name="dict_tool", context="test")
+
+    assert parsed == {"already": "parsed"}
+    assert json.loads(json.dumps(parsed)) == {"already": "parsed"}
+
+
+def test_parse_tool_call_arguments_rejects_unrepairable_json():
+    with pytest.raises(ValueError, match="broken_tool"):
+        parse_tool_call_arguments("not valid json{{{", tool_name="broken_tool", context="test")
+
+
 @pytest.mark.parametrize("part_type", ["image_url", "input_image"])
 @pytest.mark.parametrize(
     "fields",
diff --git a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
index 8a755d47817..c8d53c12aaf 100644
--- a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
+++ b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_factory.py
@@ -16,6 +16,7 @@ import pytest
 import respx
 
 import litellm
+from litellm.constants import REDACTED_BY_LITELLM
 from litellm.litellm_core_utils.prompt_templates.factory import (
     BEDROCK_DOCUMENT_PLACEHOLDER_TEXT,
     _EMPTY_TEXT_PLACEHOLDER,
@@ -38,6 +39,7 @@ from litellm.litellm_core_utils.prompt_templates.factory import (
     make_valid_bedrock_tool_name,
     ollama_pt,
     parse_mime_type,
+    requires_inline_base64_media,
     sanitize_messages_for_tool_calling,
     THOUGHT_SIGNATURE_SEPARATOR,
 )
@@ -3189,6 +3191,35 @@ def test_convert_to_anthropic_tool_result_image_with_cache_control():
     assert result["content"][1]["cache_control"]["type"] == "ephemeral"
 
 
+@pytest.mark.parametrize("tool_output", [{"result_key": "result_value"}, 42, 0, 3.5, True, False])
+def test_convert_to_anthropic_tool_result_serializes_non_string_content(tool_output):
+    from litellm.litellm_core_utils.prompt_templates.factory import (
+        convert_to_anthropic_tool_result,
+    )
+
+    result = convert_to_anthropic_tool_result({"role": "tool", "tool_call_id": "call_value", "content": tool_output})
+
+    assert result["type"] == "tool_result"
+    assert json.loads(result["content"]) == tool_output
+
+
+@pytest.mark.parametrize(
+    "tool_message",
+    [
+        {"role": "tool", "tool_call_id": "call_value", "content": None},
+        {"role": "tool", "tool_call_id": "call_value"},
+    ],
+)
+def test_convert_to_anthropic_tool_result_sends_an_empty_result_for_null_or_missing_content(tool_message):
+    from litellm.litellm_core_utils.prompt_templates.factory import (
+        convert_to_anthropic_tool_result,
+    )
+
+    result = convert_to_anthropic_tool_result(tool_message)
+
+    assert result == {"type": "tool_result", "tool_use_id": "call_value", "content": ""}
+
+
 def test_convert_to_anthropic_tool_result_image_without_cache_control():
     """
     Test that images without cache_control in tool results work correctly.
@@ -5203,6 +5234,7 @@ def test_group_tool_exchanges_is_linear_in_message_count():
 
 
 _PDF_DATA_URI = "data:application/pdf;base64," + base64.b64encode(b"%PDF-1.4 regression fixture").decode()
+_PNG_B64 = base64.b64encode(b"\x89PNG\r\n\x1a\n regression fixture").decode()
 _PNG_DATA_URI = (
     "data:image/png;base64,"
     "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mNkYPhfDwAChwGA60e6kgAAAABJRU5ErkJggg=="
@@ -5235,6 +5267,132 @@ def test_bedrock_converse_pdf_only_user_message_gets_text_block():
     assert _text_blocks(result[0]) == [BEDROCK_DOCUMENT_PLACEHOLDER_TEXT]
 
 
+@pytest.mark.parametrize(
+    ("model", "llm_provider"),
+    [
+        ("claude-sonnet-5", "anthropic"),
+        ("invoke/us.anthropic.claude-sonnet-5", "bedrock"),
+        ("claude-sonnet-5", "vertex_ai"),
+        ("claude-sonnet-5", "snowflake"),
+    ],
+)
+def test_anthropic_messages_pt_user_pdf_data_uri_becomes_document_block(model, llm_provider):
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {"type": "text", "text": "What word is in this document?"},
+                {
+                    "type": "image_url",
+                    "image_url": {"url": _PDF_DATA_URI},
+                    "cache_control": {"type": "ephemeral"},
+                },
+            ],
+        }
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model=model, llm_provider=llm_provider)
+
+    assert result[0]["content"][1] == {
+        "type": "document",
+        "source": {
+            "type": "base64",
+            "media_type": "application/pdf",
+            "data": _PDF_DATA_URI.split(",", 1)[1],
+        },
+        "cache_control": {"type": "ephemeral"},
+    }
+    assert all(block["type"] != "image" for block in result[0]["content"])
+
+
+_TEXT_B64 = base64.b64encode("the secret code word is MANGO\n".encode()).decode()
+_TEXT_DATA_URI = "data:text/plain;base64," + _TEXT_B64
+_TEXT_DATA_URI_WITH_CHARSET = "data:text/plain;charset=utf-8;base64," + _TEXT_B64
+_LATIN1_TEXT_DATA_URI = "data:text/plain;charset=iso-8859-1;base64," + base64.b64encode(
+    "the secret code word is MANGÓ\n".encode("latin-1")
+).decode()
+_OCTET_TEXT_DATA_URI = "data:application/octet-stream;base64," + _TEXT_B64
+
+
+@pytest.mark.parametrize(
+    "block, expected_text",
+    [
+        ({"type": "image_url", "image_url": {"url": _TEXT_DATA_URI}}, "the secret code word is MANGO\n"),
+        ({"type": "file", "file": {"file_data": _TEXT_DATA_URI}}, "the secret code word is MANGO\n"),
+        ({"type": "image_url", "image_url": {"url": _TEXT_DATA_URI_WITH_CHARSET}}, "the secret code word is MANGO\n"),
+        ({"type": "file", "file": {"file_data": _TEXT_DATA_URI_WITH_CHARSET}}, "the secret code word is MANGO\n"),
+        ({"type": "file", "file": {"file_data": _LATIN1_TEXT_DATA_URI}}, "the secret code word is MANGÓ\n"),
+        (
+            {"type": "image_url", "image_url": {"url": "data:TEXT/PLAIN;base64," + _TEXT_B64}},
+            "the secret code word is MANGO\n",
+        ),
+        (
+            {"type": "image_url", "image_url": {"url": _LATIN1_TEXT_DATA_URI.replace("text/plain", "TEXT/PLAIN", 1)}},
+            "the secret code word is MANGÓ\n",
+        ),
+        ({"type": "file", "file": {"file_data": "data:TEXT/PLAIN;base64," + _TEXT_B64}}, "the secret code word is MANGO\n"),
+        (
+            {"type": "file", "file": {"file_data": _OCTET_TEXT_DATA_URI, "format": "Text/Plain"}},
+            "the secret code word is MANGO\n",
+        ),
+        (
+            {"type": "image_url", "image_url": {"url": _OCTET_TEXT_DATA_URI, "format": "Text/Plain"}},
+            "the secret code word is MANGO\n",
+        ),
+    ],
+    ids=[
+        "image_url",
+        "file",
+        "image_url_charset",
+        "file_charset",
+        "file_latin1",
+        "image_url_uppercase",
+        "uppercase_latin1",
+        "file_uppercase",
+        "file_mixed_case_format",
+        "image_url_mixed_case_format",
+    ],
+)
+def test_anthropic_messages_pt_text_plain_data_uri_becomes_text_source_document(block, expected_text):
+    messages = [{"role": "user", "content": [{"type": "text", "text": "What is the code word?"}, block]}]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"][1] == {
+        "type": "document",
+        "source": {"type": "text", "media_type": "text/plain", "data": expected_text},
+    }
+
+
+def test_anthropic_messages_pt_user_png_data_uri_stays_an_image_block():
+    messages = [{"role": "user", "content": [{"type": "image_url", "image_url": {"url": _PNG_DATA_URI}}]}]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [
+        {
+            "type": "image",
+            "source": {"type": "base64", "media_type": "image/png", "data": _PNG_DATA_URI.split(",", 1)[1]},
+        }
+    ]
+
+
+@pytest.mark.parametrize(
+    ("model", "llm_provider", "expected"),
+    [
+        ("invoke/us.anthropic.claude-sonnet-5", "bedrock", True),
+        ("claude-sonnet-5", "vertex_ai", True),
+        ("claude-sonnet-5", "vertex_ai_beta", True),
+        ("claude-sonnet-5", "snowflake", False),
+        ("claude-sonnet-5", "anthropic", False),
+        ("us.anthropic.claude-sonnet-5", "bedrock", False),
+        ("claude-sonnet-5", None, False),
+    ],
+)
+def test_requires_inline_base64_media(model, llm_provider, expected):
+    assert requires_inline_base64_media(model, llm_provider) is expected
+
+
 def test_bedrock_converse_document_with_text_gets_no_extra_text_block():
     messages = [
         {
@@ -9008,3 +9166,694 @@ def test_wrong_type_template_field_in_requests_leaves_the_deployments_in_rotatio
     response = router.completion(model="template-group", messages=TEMPLATE_MESSAGES, mock_response="Blue")
 
     assert response.choices[0].message.content == "Blue"
+
+
+def test_anthropic_messages_pt_keeps_assistant_tool_use_content_block():
+    messages = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "text", "text": "let me look that up"},
+                {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {"city": "paris"}},
+            ],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {"type": "text", "text": "let me look that up"},
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {"city": "paris"}},
+    ]
+    assert result[2]["content"] == [{"type": "tool_result", "tool_use_id": "toolu_01", "content": "sunny"}]
+
+
+def test_anthropic_messages_pt_does_not_duplicate_a_tool_use_present_in_both_shapes():
+    messages = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "tool_use", "id": "functions.Bash:0", "name": "get_weather", "input": {"city": "paris"}}
+            ],
+            "tool_calls": [
+                {
+                    "id": "functions.Bash:0",
+                    "type": "function",
+                    "function": {"name": "get_weather", "arguments": '{"city": "paris"}'},
+                }
+            ],
+        },
+        {"role": "tool", "tool_call_id": "functions.Bash:0", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {"type": "tool_use", "id": "functions_Bash_0", "name": "get_weather", "input": {"city": "paris"}}
+    ]
+
+
+def test_anthropic_messages_pt_sanitizes_a_native_tool_use_id_like_its_tool_result():
+    messages = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "tool_use", "id": "functions.Bash:0", "name": "get_weather", "input": {"city": "paris"}}
+            ],
+        },
+        {"role": "tool", "tool_call_id": "functions.Bash:0", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {"type": "tool_use", "id": "functions_Bash_0", "name": "get_weather", "input": {"city": "paris"}}
+    ]
+    assert result[2]["content"] == [
+        {"type": "tool_result", "tool_use_id": "functions_Bash_0", "content": "sunny"}
+    ]
+
+
+def test_anthropic_messages_pt_normalizes_a_native_tool_use_block():
+    messages = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [
+                {
+                    "type": "tool_use",
+                    "index": 0,
+                    "id": "toolu_01",
+                    "name": "get_weather",
+                    "input": '{"city": "paris"}',
+                    "cache_control": {"type": "ephemeral"},
+                }
+            ],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {
+            "type": "tool_use",
+            "id": "toolu_01",
+            "name": "get_weather",
+            "input": {"city": "paris"},
+            "cache_control": {"type": "ephemeral"},
+        }
+    ]
+
+
+@pytest.mark.parametrize(
+    ("url", "format_override", "expected"),
+    [
+        (
+            "data:application/pdf;base64," + _PNG_B64,
+            "image/png",
+            {"type": "image", "source": {"type": "base64", "media_type": "image/png", "data": _PNG_B64}},
+        ),
+        (
+            "data:image/png;base64,JVBERi0=",
+            "application/pdf",
+            {"type": "document", "source": {"type": "base64", "media_type": "application/pdf", "data": "JVBERi0="}},
+        ),
+        (
+            _PDF_DATA_URI,
+            "image/png",
+            {
+                "type": "document",
+                "source": {"type": "base64", "media_type": "application/pdf", "data": _PDF_DATA_URI.split(",", 1)[1]},
+            },
+        ),
+    ],
+    ids=["png_bytes_under_a_pdf_uri_declared_png", "png_uri_declared_pdf", "pdf_bytes_declared_png"],
+)
+def test_anthropic_messages_pt_honours_an_explicit_format_over_the_data_uri(url, format_override, expected):
+    messages = [
+        {"role": "user", "content": [{"type": "image_url", "image_url": {"url": url, "format": format_override}}]}
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [expected]
+
+
+def test_anthropic_messages_pt_collapses_native_tool_use_blocks_sharing_an_id():
+    messages = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "tool_use", "id": "functions.Bash:0", "name": "get_weather", "input": {"city": "paris"}},
+                {"type": "tool_use", "id": "functions_Bash_0", "name": "get_weather", "input": {"city": "london"}},
+            ],
+        },
+        {"role": "tool", "tool_call_id": "functions.Bash:0", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {"type": "tool_use", "id": "functions_Bash_0", "name": "get_weather", "input": {"city": "paris"}}
+    ]
+
+
+@pytest.mark.parametrize(
+    "image_url",
+    [{"url": _PDF_DATA_URI}, {"url": _PDF_DATA_URI, "format": "image/png"}],
+    ids=["no-format", "declared-png"],
+)
+def test_anthropic_messages_pt_tool_result_pdf_data_uri_becomes_a_document_block(image_url):
+    messages = [
+        {"role": "user", "content": "fetch the invoice"},
+        {
+            "role": "assistant",
+            "content": [{"type": "tool_use", "id": "toolu_01", "name": "fetch_invoice", "input": {}}],
+        },
+        {
+            "role": "tool",
+            "tool_call_id": "toolu_01",
+            "content": [{"type": "image_url", "image_url": image_url}],
+        },
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[2]["content"] == [
+        {
+            "type": "tool_result",
+            "tool_use_id": "toolu_01",
+            "content": [
+                {
+                    "type": "document",
+                    "source": {
+                        "type": "base64",
+                        "media_type": "application/pdf",
+                        "data": _PDF_DATA_URI.split(",", 1)[1],
+                    },
+                }
+            ],
+        }
+    ]
+
+
+def test_anthropic_messages_pt_text_document_keeps_charset_named_by_the_data_uri():
+    latin1_data_uri: Final = "data:text/plain;charset=iso-8859-1;base64," + base64.b64encode(
+        "café".encode("iso-8859-1")
+    ).decode()
+    messages = [
+        {
+            "role": "user",
+            "content": [{"type": "image_url", "image_url": {"url": latin1_data_uri, "format": "text/plain"}}],
+        }
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [
+        {"type": "document", "source": {"type": "text", "media_type": "text/plain", "data": "café"}}
+    ]
+
+
+@pytest.mark.parametrize(
+    ("charset", "text"),
+    [
+        ("shift_jis", "日本語"),
+        ("windows-1252", "café"),
+        ("KOI8-R", "привет"),
+        ("utf-16", "naïve"),
+        ("iso-8859-9", "İstanbul"),
+        ("iso-8859-11", "ไทย"),
+        ("tis-620", "ไทย"),
+        ("gb2312", "中文"),
+        ("big5-hkscs", "香港"),
+        ("ms932", "日本語"),
+    ],
+)
+def test_anthropic_messages_pt_reads_a_text_attachment_in_a_legacy_encoding_its_data_uri_names(charset, text):
+    data_uri: Final = f"data:text/plain;charset={charset};base64," + base64.b64encode(text.encode(charset)).decode()
+    messages = [{"role": "user", "content": [{"type": "file", "file": {"file_data": data_uri}}]}]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [
+        {"type": "document", "source": {"type": "text", "media_type": "text/plain", "data": text}}
+    ]
+
+
+@pytest.mark.parametrize("charset", ["punycode", "utf-7"])
+def test_anthropic_messages_pt_rejects_a_text_attachment_charset_that_is_not_a_supported_text_encoding(charset):
+    data_uri: Final = f"data:text/plain;charset={charset};base64," + base64.b64encode(b"abc").decode()
+    messages = [{"role": "user", "content": [{"type": "file", "file": {"file_data": data_uri}}]}]
+
+    with pytest.raises(litellm.BadRequestError, match=f"unsupported encoding: {charset}"):
+        anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+
+def test_anthropic_messages_pt_native_tool_use_input_survives_guardrail_redaction():
+    messages = [
+        {"role": "user", "content": "hi"},
+        {
+            "role": "assistant",
+            "content": [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": REDACTED_BY_LITELLM}],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]
+
+
+def test_anthropic_messages_pt_drops_a_native_tool_use_nobody_answered():
+    messages = [
+        {"role": "user", "content": "what is the weather"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "text", "text": "checking"},
+                {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}},
+            ],
+        },
+        {"role": "user", "content": "never mind, tell me a joke"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [{"type": "text", "text": "checking"}]
+
+
+def _empty_text_beside_native_tool_use(follow_up: dict[str, object]) -> list[dict[str, object]]:
+    return [
+        {"role": "user", "content": "what is the weather"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "text", "text": " "},
+                {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}},
+            ],
+        },
+        follow_up,
+    ]
+
+
+@pytest.mark.parametrize("modify_params", [False, True])
+def test_anthropic_messages_pt_drops_empty_text_beside_an_answered_native_tool_use(monkeypatch, modify_params):
+    monkeypatch.setattr(litellm, "modify_params", modify_params)
+    messages: Final = _empty_text_beside_native_tool_use({"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"})
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]
+
+
+@pytest.mark.parametrize("modify_params", [False, True])
+def test_anthropic_messages_pt_keeps_the_placeholder_beside_an_unanswered_native_tool_use(monkeypatch, modify_params):
+    monkeypatch.setattr(litellm, "modify_params", modify_params)
+    messages: Final = _empty_text_beside_native_tool_use({"role": "user", "content": "never mind"})
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [{"type": "text", "text": _EMPTY_TEXT_PLACEHOLDER}]
+
+
+def _answered_native_tool_use(tool_use: dict[str, object]) -> list[dict[str, object]]:
+    return [
+        {"role": "user", "content": "what is the weather"},
+        {"role": "assistant", "content": [tool_use]},
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+
+@pytest.mark.parametrize(
+    "tool_use",
+    [
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": "[1, 2]"},
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": [1, 2]},
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather"},
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": "{not json"},
+    ],
+    ids=["json-array-string", "list", "missing", "unparseable"],
+)
+def test_anthropic_messages_pt_native_tool_use_input_that_is_not_an_object_follows_drop_params(tool_use):
+    messages: Final = _answered_native_tool_use(tool_use)
+
+    with pytest.raises(ValueError, match="get_weather"):
+        anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+    dropped: Final = anthropic_messages_pt(
+        messages=messages, model="claude-sonnet-5", llm_provider="anthropic", drop_params=True
+    )
+
+    assert dropped[1]["content"] == [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]
+
+
+def test_anthropic_messages_pt_unparseable_tool_call_arguments_follow_drop_params():
+    messages: Final = [
+        {"role": "user", "content": "what is the weather"},
+        {
+            "role": "assistant",
+            "content": None,
+            "tool_calls": [
+                {"id": "toolu_01", "type": "function", "function": {"name": "get_weather", "arguments": "{not json"}}
+            ],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    with pytest.raises(ValueError, match="get_weather"):
+        anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+    dropped: Final = anthropic_messages_pt(
+        messages=messages, model="claude-sonnet-5", llm_provider="anthropic", drop_params=True
+    )
+
+    assert dropped[1]["content"] == [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]
+
+
+_NAMED_PDF_DATA_URI = "data:application/pdf;name=report.pdf;base64," + base64.b64encode(b"%PDF-1.4 named").decode()
+
+
+@pytest.mark.parametrize(
+    "block",
+    [
+        {"type": "image_url", "image_url": {"url": _NAMED_PDF_DATA_URI}},
+        {"type": "file", "file": {"file_data": _NAMED_PDF_DATA_URI}},
+    ],
+    ids=["image_url", "file"],
+)
+def test_anthropic_messages_pt_sends_a_named_pdf_under_its_bare_media_type(block):
+    result = anthropic_messages_pt(
+        messages=[{"role": "user", "content": [block]}], model="claude-sonnet-5", llm_provider="anthropic"
+    )
+
+    assert result[0]["content"] == [
+        {
+            "type": "document",
+            "source": {
+                "type": "base64",
+                "media_type": "application/pdf",
+                "data": _NAMED_PDF_DATA_URI.split(",", 1)[1],
+            },
+        }
+    ]
+
+
+def test_anthropic_messages_pt_keeps_a_pdf_a_document_when_the_format_is_generic():
+    messages = [
+        {"role": "user", "content": "fetch the invoice"},
+        {
+            "role": "assistant",
+            "content": [{"type": "tool_use", "id": "toolu_01", "name": "fetch_invoice", "input": {}}],
+        },
+        {
+            "role": "tool",
+            "tool_call_id": "toolu_01",
+            "content": [
+                {
+                    "type": "image_url",
+                    "image_url": {"url": _PDF_DATA_URI, "format": "application/octet-stream"},
+                }
+            ],
+        },
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[2]["content"] == [
+        {
+            "type": "tool_result",
+            "tool_use_id": "toolu_01",
+            "content": [
+                {
+                    "type": "document",
+                    "source": {
+                        "type": "base64",
+                        "media_type": "application/pdf",
+                        "data": _PDF_DATA_URI.split(",", 1)[1],
+                    },
+                }
+            ],
+        }
+    ]
+
+
+def test_anthropic_messages_pt_drops_data_uri_parameters_the_format_replaces():
+    png_data_uri: Final = "data:image/png;name=diagram.png;base64," + base64.b64encode(b"\x89PNG\r\n\x1a\n").decode()
+    messages = [
+        {
+            "role": "user",
+            "content": [{"type": "image_url", "image_url": {"url": png_data_uri, "format": "image/png"}}],
+        }
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [
+        {
+            "type": "image",
+            "source": {"type": "base64", "media_type": "image/png", "data": png_data_uri.split(",", 1)[1]},
+        }
+    ]
+
+
+def test_anthropic_messages_pt_rejects_a_text_attachment_it_cannot_decode():
+    undeclared_latin1: Final = "data:text/plain;base64," + base64.b64encode(
+        "the secret code word is caf\xe9".encode("iso-8859-1") * 200
+    ).decode()
+    messages = [
+        {
+            "role": "user",
+            "content": [{"type": "image_url", "image_url": {"url": undeclared_latin1, "format": "text/plain"}}],
+        }
+    ]
+
+    with pytest.raises(litellm.BadRequestError) as raised:
+        anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert "utf-8" in str(raised.value)
+    assert undeclared_latin1.split(",", 1)[1] not in str(raised.value)
+    assert "file block's format" in str(raised.value)
+
+
+def test_anthropic_messages_pt_reads_a_text_file_block_in_the_charset_its_format_names():
+    undeclared_latin1: Final = "data:text/plain;base64," + base64.b64encode("caf\xe9".encode("iso-8859-1")).decode()
+    messages: Final = [
+        {
+            "role": "user",
+            "content": [
+                {"type": "file", "file": {"file_data": undeclared_latin1, "format": "text/plain;charset=iso-8859-1"}}
+            ],
+        }
+    ]
+
+    result: Final = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [
+        {"type": "document", "source": {"type": "text", "media_type": "text/plain", "data": "café"}}
+    ]
+
+
+@pytest.mark.parametrize("native_input", [{"city": "lyon"}, "[1, 2]"])
+def test_anthropic_messages_pt_sends_tool_calls_arguments_over_a_native_tool_use_with_the_same_id(native_input):
+    messages: Final = [
+        {"role": "user", "content": "what is the weather in paris"},
+        {
+            "role": "assistant",
+            "content": [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": native_input}],
+            "tool_calls": [
+                {
+                    "id": "toolu_01",
+                    "type": "function",
+                    "function": {"name": "get_weather", "arguments": '{"city": "paris"}'},
+                }
+            ],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result: Final = anthropic_messages_pt(messages=messages, model="claude-sonnet-5-5", llm_provider="anthropic")
+
+    assert result[1]["content"] == [
+        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {"city": "paris"}}
+    ]
+
+
+@pytest.mark.parametrize(("drop_params", "expected_input"), [(True, {}), (False, [1, 2])])
+def test_anthropic_messages_pt_tool_call_arguments_that_are_not_an_object_follow_drop_params(
+    drop_params, expected_input
+):
+    messages: Final = [
+        {"role": "user", "content": "what is the weather"},
+        {
+            "role": "assistant",
+            "content": None,
+            "tool_calls": [
+                {"id": "toolu_01", "type": "function", "function": {"name": "get_weather", "arguments": "[1, 2]"}}
+            ],
+        },
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result: Final = anthropic_messages_pt(
+        messages=messages, model="claude-sonnet-5-5", llm_provider="anthropic", drop_params=drop_params
+    )
+
+    assert result[1]["content"][0]["input"] == expected_input
+
+
+_PDF_PAYLOAD: Final = _PDF_DATA_URI.split(",", 1)[1]
+
+
+@pytest.mark.parametrize(
+    "block",
+    [
+        {"type": "file", "file": {"file_data": "data:application/octet-stream;base64," + _PDF_PAYLOAD}},
+        {"type": "file", "file": {"file_data": "data:image/png;base64," + _PDF_PAYLOAD}},
+        {"type": "file", "file": {"file_data": _PDF_DATA_URI, "format": "text/plain"}},
+        {"type": "image_url", "image_url": {"url": _PDF_DATA_URI, "format": "text/plain"}},
+    ],
+    ids=["file-octet-stream", "file-image-png", "file-format-text", "image-url-format-text"],
+)
+def test_anthropic_messages_pt_sends_pdf_bytes_as_a_pdf_document_whatever_the_label(block):
+    result: Final = anthropic_messages_pt(
+        messages=[{"role": "user", "content": [block]}], model="claude-sonnet-5-5", llm_provider="anthropic"
+    )
+
+    assert result[0]["content"] == [
+        {"type": "document", "source": {"type": "base64", "media_type": "application/pdf", "data": _PDF_PAYLOAD}}
+    ]
+
+
+def test_gemini_inline_data_carries_the_format_it_was_given():
+    text_data_uri: Final = "data:text/plain;charset=utf-8;base64," + base64.b64encode(b"MANGO").decode()
+    messages: Final = [
+        {"role": "user", "content": [{"type": "image_url", "image_url": {"url": text_data_uri, "format": "text/plain"}}]}
+    ]
+
+    contents: Final = gemini_convert_messages_with_history(messages=messages, model="gemini-3.8-flash")
+
+    assert contents[0]["parts"][0]["inline_data"]["mime_type"] == "text/plain"
+
+
+def _parallel_native_tool_use_seconds(calls: int) -> float:
+    answers: Final = tuple(
+        {"role": "tool", "tool_call_id": f"functions.get_weather:{index}", "content": "sunny"} for index in range(calls)
+    )
+    messages: Final = [
+        {"role": "user", "content": "weather everywhere"},
+        {
+            "role": "assistant",
+            "content": [
+                {"type": "tool_use", "id": f"functions.get_weather:{index}", "name": "get_weather", "input": {}}
+                for index in range(calls)
+            ],
+        },
+        *answers,
+    ]
+
+    def once() -> float:
+        started: Final = time.perf_counter()
+        result: Final = anthropic_messages_pt(messages=messages, model="claude-sonnet-5-5", llm_provider="anthropic")
+        elapsed: Final = time.perf_counter() - started
+        assert [block["id"] for block in result[1]["content"]] == [
+            f"functions_get_weather_{index}" for index in range(calls)
+        ]
+        return elapsed
+
+    return min(once() for _ in range(3))
+
+
+def test_anthropic_messages_pt_cost_grows_linearly_with_parallel_native_tool_uses():
+    growth: Final = _parallel_native_tool_use_seconds(1600) / _parallel_native_tool_use_seconds(400)
+
+    assert growth < 11.0, f"cost grew {growth:.1f}x for 4x the tool uses"
+
+
+def test_anthropic_messages_pt_keeps_a_native_tool_use_answered_by_a_tool_message_under_modify_params(monkeypatch):
+    monkeypatch.setattr(litellm, "modify_params", True)
+    messages = [
+        {"role": "user", "content": "what is the weather"},
+        {"role": "assistant", "content": [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]},
+        {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+    ]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[1:] == [
+        {"role": "assistant", "content": [{"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {}}]},
+        {"role": "user", "content": [{"type": "tool_result", "tool_use_id": "toolu_01", "content": "sunny"}]},
+    ]
+
+
+@pytest.mark.parametrize(
+    "pdf_format, content_type",
+    ((None, "application/pdf"), ("Application/PDF", "application/pdf"), (None, "image/png"), ("image/png", "application/pdf")),
+)
+def test_create_anthropic_image_param_sends_a_downloaded_pdf_as_a_document(monkeypatch, pdf_format, content_type):
+    from litellm.litellm_core_utils.prompt_templates.image_handling import in_memory_cache
+
+    pdf_bytes = b"%PDF-1.4\n1 0 obj\n"
+    mock_client = MagicMock()
+    mock_client.get.return_value = httpx.Response(200, content=pdf_bytes, headers={"Content-Type": content_type})
+    monkeypatch.setattr(litellm, "user_url_validation", False, raising=False)
+    monkeypatch.setattr(litellm, "module_level_client", mock_client, raising=False)
+    in_memory_cache.flush_cache()
+
+    block = create_anthropic_image_param(
+        {"url": "https://example.com/report.pdf", "format": pdf_format}, is_bedrock_invoke=True
+    )
+
+    assert block == {
+        "type": "document",
+        "source": {"type": "base64", "media_type": "application/pdf", "data": base64.b64encode(pdf_bytes).decode()},
+    }
+
+
+def test_create_anthropic_image_param_links_an_https_pdf_as_a_document_only_when_format_says_pdf():
+    url = "https://example.com/report.pdf"
+
+    assert create_anthropic_image_param({"url": url, "format": "application/pdf"}) == {
+        "type": "document",
+        "source": {"type": "url", "url": url},
+    }
+    assert create_anthropic_image_param({"url": url, "format": "Application/PDF"}) == {
+        "type": "document",
+        "source": {"type": "url", "url": url},
+    }
+    assert create_anthropic_image_param({"url": url, "format": "image/png"}) == {
+        "type": "image",
+        "source": {"type": "url", "url": url},
+    }
+
+
+@pytest.mark.parametrize("bad_format", (7, ["image/png"]), ids=("int", "list"))
+@pytest.mark.parametrize(
+    "block, expected",
+    (
+        (
+            {"type": "image_url", "image_url": {"url": "https://example.com/cat.png"}},
+            {"type": "image", "source": {"type": "url", "url": "https://example.com/cat.png"}},
+        ),
+        (
+            {"type": "image_url", "image_url": {"url": _PNG_DATA_URI}},
+            {"type": "image", "source": {"type": "base64", "media_type": "image/png", "data": _PNG_DATA_URI.split(",", 1)[1]}},
+        ),
+        (
+            {"type": "file", "file": {"file_id": "file_abc"}},
+            {"type": "container_upload", "file_id": "file_abc"},
+        ),
+    ),
+    ids=("https_link", "data_uri", "file_id"),
+)
+def test_anthropic_messages_pt_ignores_a_format_that_is_not_a_string(bad_format, block, expected):
+    payload_key = "image_url" if block["type"] == "image_url" else "file"
+    messages = [{"role": "user", "content": [{**block, payload_key: {**block[payload_key], "format": bad_format}}]}]
+
+    result = anthropic_messages_pt(messages=messages, model="claude-sonnet-5", llm_provider="anthropic")
+
+    assert result[0]["content"] == [expected]
diff --git a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_mid_conversation_system.py b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_mid_conversation_system.py
index aab57b87a90..74c488abeb5 100644
--- a/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_mid_conversation_system.py
+++ b/tests/unit/litellm_core_utils/prompt_templates/test_litellm_core_utils_prompt_templates_mid_conversation_system.py
@@ -536,6 +536,23 @@ def test_flagged_placement_keeps_a_system_before_an_assistant_turn_whose_empty_t
     assert _roles(placed) == ["user", "system", "assistant", "user"]
 
 
+def test_flagged_placement_keeps_a_system_before_an_answered_native_tool_use():
+    placed = place_mid_conversation_system(
+        [
+            {"role": "user", "content": "weather?"},
+            {"role": "system", "content": "Be terse."},
+            {
+                "role": "assistant",
+                "content": [{"type": "tool_use", "id": "functions.get_weather:0", "name": "get_weather", "input": {}}],
+            },
+            {"role": "tool", "tool_call_id": "functions.get_weather:0", "content": "sunny"},
+        ],
+        supports_mid_conversation_system=True,
+    )
+
+    assert _roles(placed) == ["user", "system", "assistant", "tool"]
+
+
 def test_anthropic_system_blocks_keeps_text_parts_with_their_cache_control_and_drops_the_rest():
     run = [
         {"role": "system", "content": "one", "cache_control": {"type": "ephemeral", "ttl": "1h"}},
diff --git a/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py b/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py
index 13ff11e8a3f..e574eef26b5 100644
--- a/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py
+++ b/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py
@@ -1,3 +1,4 @@
+import base64
 import copy
 import json
 import logging
@@ -10465,14 +10466,14 @@ def test_chat_transform_request_keeps_a_conversion_error_that_a_dropped_orphan_a
                     "tool_calls": [
                         {
                             **_WEATHER_CALL["tool_calls"][0],
-                            "function": {"name": "get_weather", "arguments": {"city": "Paris"}},
+                            "function": {"name": "get_weather", "arguments": ["Paris"]},
                         }
                     ],
                 },
                 {"role": "tool", "tool_call_id": "toolu_01", "content": "rain"},
             ],
-            "'dict' object has no attribute 'strip'",
-            id="object_tool_call_arguments",
+            "'list' object has no attribute 'strip'",
+            id="list_tool_call_arguments",
         ),
         pytest.param(
             [{"role": "user", "content": [{"type": "image_url", "image_url": ["x"]}]}],
@@ -10726,3 +10727,27 @@ def test_claude_cache_control_cap_does_not_count_a_message_level_hint_that_list_
 
     assert sorted(_cached_texts(body)) == ["system prompt", "turn 1", "turn 2", "turn 3"]
     assert json.dumps(body).count('"cache_control"') == 4
+
+
+def test_completion_rejecting_a_text_attachment_does_not_echo_the_request_back(respx_mock: respx.MockRouter):
+    route: Final = respx_mock.post("https://api.anthropic.com/v1/messages").mock(return_value=httpx.Response(500))
+    attachment_data: Final = base64.b64encode(b"attachment body that stays out of the error " * 64).decode()
+
+    with pytest.raises(litellm.BadRequestError) as exc_info:
+        litellm.completion(
+            model="anthropic/claude-sonnet-4-5-20250929",
+            api_key="mock_api_key",
+            messages=[
+                {
+                    "role": "user",
+                    "content": [
+                        {"type": "text", "text": "Summarize this file"},
+                        {"type": "file", "file": {"file_data": f"data:text/plain;charset=punycode;base64,{attachment_data}"}},
+                    ],
+                }
+            ],
+        )
+
+    assert "unsupported encoding: punycode" in str(exc_info.value)
+    assert attachment_data not in str(exc_info.value)
+    assert route.call_count == 0
diff --git a/tests/unit/llms/anthropic/test_anthropic_count_tokens_transformation.py b/tests/unit/llms/anthropic/test_anthropic_count_tokens_transformation.py
index aa7fa2727b4..973c1a29111 100644
--- a/tests/unit/llms/anthropic/test_anthropic_count_tokens_transformation.py
+++ b/tests/unit/llms/anthropic/test_anthropic_count_tokens_transformation.py
@@ -88,6 +88,56 @@ def test_count_translates_openai_images_without_mutating_input(
     assert messages == original
 
 
+@pytest.mark.parametrize(
+    "config_type", (AnthropicCountTokensConfig, AzureAIAnthropicCountTokensConfig)
+)
+def test_count_sends_a_pdf_image_url_as_the_document_the_chat_request_sends(
+    config_type: type[AnthropicCountTokensConfig],
+) -> None:
+    pdf_url: Final = "data:application/pdf;base64," + b64encode(b"%PDF-1.4 count fixture").decode()
+    messages: Final[list[dict[str, JsonValue]]] = [
+        {"role": "user", "content": [{"type": "image_url", "image_url": {"url": pdf_url}}]}
+    ]
+
+    counted: Final = config_type().transform_request_to_count_tokens(model="claude-opus-5-5", messages=messages)
+    sent: Final = AnthropicConfig().transform_request(
+        model="claude-opus-5-5", messages=deepcopy(messages), optional_params={}, litellm_params={}, headers={}
+    )
+
+    assert counted["messages"] == sent["messages"]
+    assert counted["messages"][0]["content"][0]["type"] == "document"
+
+
+@pytest.mark.usefixtures("httpx_transport_clients")
+@pytest.mark.parametrize(
+    "config_type", (AnthropicCountTokensConfig, AzureAIAnthropicCountTokensConfig)
+)
+@pytest.mark.parametrize("pdf_format", (None, "application/pdf"))
+def test_count_sends_a_linked_pdf_as_a_document(
+    config_type: type[AnthropicCountTokensConfig],
+    pdf_format: str | None,
+) -> None:
+    pdf_bytes: Final = b"%PDF-1.4 linked count fixture"
+    pdf_url: Final = f"https://1.1.1.1/{config_type.__name__}-{pdf_format}.pdf"
+    image_url: Final[dict[str, JsonValue]] = {"url": pdf_url} if pdf_format is None else {
+        "url": pdf_url, "format": pdf_format
+    }
+    messages: Final[list[dict[str, JsonValue]]] = [
+        {"role": "user", "content": [{"type": "image_url", "image_url": image_url}]}
+    ]
+
+    with respx.mock:
+        respx.get(pdf_url).mock(
+            return_value=httpx.Response(200, content=pdf_bytes, headers={"Content-Type": "application/pdf"})
+        )
+        counted: Final = config_type().transform_request_to_count_tokens(model="claude-opus-5-5", messages=messages)
+
+    assert counted["messages"][0]["content"][0] == {
+        "type": "document",
+        "source": {"type": "base64", "media_type": "application/pdf", "data": b64encode(pdf_bytes).decode()},
+    }
+
+
 @pytest.mark.parametrize(
     "config_type", (AnthropicCountTokensConfig, AzureAIAnthropicCountTokensConfig)
 )
diff --git a/tests/unit/llms/anthropic/test_message_sanitization.py b/tests/unit/llms/anthropic/test_message_sanitization.py
index 0afd443d07a..1a0007ba1e1 100644
--- a/tests/unit/llms/anthropic/test_message_sanitization.py
+++ b/tests/unit/llms/anthropic/test_message_sanitization.py
@@ -449,7 +449,7 @@ class TestMessageSanitization:
             ],
         }
 
-        sanitized = _sanitize_empty_text_content(message)
+        sanitized = _sanitize_empty_text_content(message, frozenset)
 
         assert [b["type"] for b in sanitized["content"]] == ["thinking"]
         assert PLACEHOLDER not in json.dumps(sanitized)
diff --git a/tests/unit/llms/bedrock/count_tokens/test_bedrock_token_counter.py b/tests/unit/llms/bedrock/count_tokens/test_bedrock_token_counter.py
index 30063936b2b..72cf544b95a 100644
--- a/tests/unit/llms/bedrock/count_tokens/test_bedrock_token_counter.py
+++ b/tests/unit/llms/bedrock/count_tokens/test_bedrock_token_counter.py
@@ -392,6 +392,24 @@ async def test_claude_count_rejects_a_lone_responses_tool_without_calling_bedroc
     assert bedrock.posted_hosts() == ()
 
 
+@pytest.mark.asyncio
+async def test_claude_count_rejects_a_text_attachment_it_cannot_decode_without_calling_bedrock() -> None:
+    bedrock: Final = _Bedrock(runtime=(200, {"inputTokens": 412}), mantle=(200, {"input_tokens": 2177}))
+    text_attachment: Final = "data:text/plain;charset=bogus-cs;base64," + base64.b64encode(b"hello").decode()
+
+    result: Final = await _counter(bedrock).count_tokens(
+        model_to_use="bedrock_mantle/anthropic.claude-opus-5-5",
+        messages=[{"role": "user", "content": [{"type": "image_url", "image_url": {"url": text_attachment}}]}],
+        contents=None,
+        deployment=DEPLOYMENT,
+    )
+
+    assert result is not None
+    assert (result.error, result.status_code, result.rejected_before_provider_call) == (True, 400, True)
+    assert "bogus-cs" in (result.error_message or "")
+    assert bedrock.posted_hosts() == ()
+
+
 _CLAUDE_REPLY: Final = {
     "id": "msg_1",
     "type": "message",
diff --git a/tests/unit/llms/snowflake/chat/test_snowflake_chat_transformation.py b/tests/unit/llms/snowflake/chat/test_snowflake_chat_transformation.py
index a31f15551e9..f907e92e4ab 100644
--- a/tests/unit/llms/snowflake/chat/test_snowflake_chat_transformation.py
+++ b/tests/unit/llms/snowflake/chat/test_snowflake_chat_transformation.py
@@ -14,12 +14,17 @@ from unittest.mock import AsyncMock, patch, Mock, MagicMock
 
 import httpx
 import pytest
+import respx
 
 import litellm
 from litellm import completion, acompletion
 from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler, HTTPHandler
 from litellm.llms.anthropic.messages.adapters.transformation import LiteLLMAnthropicMessagesAdapter
-from litellm.llms.snowflake.chat.transformation import SnowflakeConfig, SnowflakeStreamingHandler
+from litellm.llms.snowflake.chat.transformation import (
+    SnowflakeConfig,
+    SnowflakeException,
+    SnowflakeStreamingHandler,
+)
 from litellm.types.utils import ModelResponse
 
 
@@ -354,6 +359,15 @@ class TestSnowflakeCortexClaudeFixes:
         )
         assert body["system"] == [{"type": "text", "text": "You are helpful", "cache_control": {"type": "ephemeral"}}]
 
+    def test_string_system_prompt_keeps_its_message_cache_control_without_ttl(self):
+        body = self._transform(
+            [
+                {"role": "system", "content": "You are helpful", "cache_control": {"type": "ephemeral", "ttl": "1h"}},
+                {"role": "user", "content": "hi"},
+            ]
+        )
+        assert body["system"] == [{"type": "text", "text": "You are helpful", "cache_control": {"type": "ephemeral"}}]
+
     def test_direct_system_param_is_normalized(self):
         body = self._transform(
             [{"role": "user", "content": "hi"}],
@@ -422,6 +436,23 @@ class TestSnowflakeCortexClaudeFixes:
             {"type": "image", "source": {"type": "base64", "media_type": "image/jpeg", "data": "ZmFrZQ=="}}
         ]
 
+    def test_remote_image_urls_are_inlined_as_base64(self):
+        with respx.mock(assert_all_called=True) as respx_mock:
+            respx_mock.get("https://example.com/cat.png").respond(
+                content=b"fake", headers={"Content-Type": "image/png"}
+            )
+            body = self._transform(
+                [
+                    {
+                        "role": "user",
+                        "content": [{"type": "image_url", "image_url": {"url": "https://example.com/cat.png"}}],
+                    }
+                ]
+            )
+        assert body["messages"][0]["content"] == [
+            {"type": "image", "source": {"type": "base64", "media_type": "image/png", "data": "ZmFrZQ=="}}
+        ]
+
     def test_tool_result_image_list_is_converted(self):
         body = self._transform(
             [
@@ -458,7 +489,7 @@ class TestSnowflakeCortexClaudeFixes:
                     },
                 ]
             )
-            tool_result = body["messages"][1]["content"][0]
+            tool_result = body["messages"][0]["content"][1]
             assert tool_result["cache_control"] == {"type": "ephemeral"}, tool_content
 
     def test_pdf_data_uri_becomes_a_document_block(self):
@@ -524,7 +555,7 @@ class TestSnowflakeCortexClaudeFixes:
                 },
             ]
         )
-        assert body["messages"][1]["content"][0]["content"] == [
+        assert body["messages"][0]["content"][1]["content"] == [
             {"type": "text", "text": "first"},
             {"type": "image", "source": {"type": "base64", "media_type": "image/png", "data": "ZmFrZQ=="}},
             {"type": "text", "text": "last"},
@@ -534,7 +565,10 @@ class TestSnowflakeCortexClaudeFixes:
         body = self._transform(
             [{"role": "user", "content": "look"}, {"role": "tool", "tool_call_id": "call_1", "content": "done"}]
         )
-        assert body["messages"][1]["content"][0]["content"] == "done"
+        assert body["messages"][0]["content"] == [
+            {"type": "text", "text": "look"},
+            {"type": "tool_result", "tool_use_id": "call_1", "content": "done"},
+        ]
 
     def test_anthropic_tool_schema_strips_only_top_level_schema_key(self):
         tools = [
@@ -687,6 +721,123 @@ class TestSnowflakeCortexClaudeFixes:
             ],
         }
 
+    def test_assistant_tool_use_content_block_survives_the_transform(self):
+        body = self._transform(
+            [
+                {"role": "user", "content": "what is the weather in paris"},
+                {
+                    "role": "assistant",
+                    "content": [
+                        {"type": "text", "text": "let me look that up"},
+                        {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {"city": "paris"}},
+                    ],
+                },
+                {"role": "tool", "tool_call_id": "toolu_01", "content": "sunny"},
+            ]
+        )
+        assert body["messages"][1]["content"] == [
+            {"type": "text", "text": "let me look that up"},
+            {"type": "tool_use", "id": "toolu_01", "name": "get_weather", "input": {"city": "paris"}},
+        ]
+        assert body["messages"][2]["content"] == [
+            {"type": "tool_result", "tool_use_id": "toolu_01", "content": "sunny"}
+        ]
+
+    def test_native_tool_use_id_is_sanitized_like_its_tool_result(self):
+        body = self._transform(
+            [
+                {"role": "user", "content": "what is the weather in paris"},
+                {
+                    "role": "assistant",
+                    "content": [
+                        {
+                            "type": "tool_use",
+                            "id": "functions.Bash:0",
+                            "name": "get_weather",
+                            "input": {"city": "paris"},
+                        }
+                    ],
+                },
+                {"role": "tool", "tool_call_id": "functions.Bash:0", "content": "sunny"},
+            ]
+        )
+        assert body["messages"][1]["content"] == [
+            {"type": "tool_use", "id": "functions_Bash_0", "name": "get_weather", "input": {"city": "paris"}}
+        ]
+        assert body["messages"][2]["content"] == [
+            {"type": "tool_result", "tool_use_id": "functions_Bash_0", "content": "sunny"}
+        ]
+
+    def test_system_prompt_keeps_only_its_text_parts(self):
+        body = self._transform(
+            [
+                {
+                    "role": "system",
+                    "content": [
+                        {"type": "text", "text": "be terse"},
+                        {"type": "image_url", "image_url": {"url": "data:image/png;base64,iVBORw0KGgo="}},
+                    ],
+                },
+                {"role": "user", "content": "hi"},
+            ]
+        )
+        assert body["system"] == [{"type": "text", "text": "be terse"}]
+
+    _AUDIO_TURN = (
+        {
+            "role": "user",
+            "content": [
+                {"type": "text", "text": "hear"},
+                {"type": "input_audio", "input_audio": {"data": "UklGRg==", "format": "wav"}},
+            ],
+        },
+    )
+
+    def test_user_part_cortex_claude_cannot_take_is_a_400_naming_it(self):
+        with pytest.raises(SnowflakeException) as exc_info:
+            self._transform(list(self._AUDIO_TURN))
+        assert exc_info.value.status_code == 400
+        assert "input_audio" in str(exc_info.value)
+
+    @pytest.mark.parametrize(
+        ("part", "named"),
+        (("hello", "untyped str"), ({"type": "image_url", "image_url": {"detail": "low"}}, "url")),
+    )
+    def test_malformed_user_part_is_a_400_naming_it(self, part, named):
+        with pytest.raises(SnowflakeException) as exc_info:
+            self._transform([{"role": "user", "content": [part]}])
+        assert exc_info.value.status_code == 400
+        assert named in str(exc_info.value)
+
+    def test_drop_params_drops_a_user_part_cortex_claude_cannot_take(self):
+        body = SnowflakeConfig().transform_request(
+            model="snowflake/claude-sonnet-4-6",
+            messages=list(self._AUDIO_TURN),
+            optional_params={},
+            litellm_params={"drop_params": True},
+            headers={},
+        )
+        assert body["messages"] == [{"role": "user", "content": [{"type": "text", "text": "hear"}]}]
+
+    def test_unknown_charset_on_a_text_attachment_is_a_400(self):
+        with pytest.raises(SnowflakeException) as exc_info:
+            self._transform(
+                [
+                    {
+                        "role": "user",
+                        "content": [
+                            {
+                                "type": "file",
+                                "file": {"file_data": "data:text/plain;charset=not-a-charset;base64,aGVsbG8="},
+                            }
+                        ],
+                    }
+                ]
+            )
+
+        assert exc_info.value.status_code == 400
+        assert "not-a-charset" in str(exc_info.value)
+
     def test_thinking_only_assistant_turn_sends_no_empty_text_block(self):
         """Anthropic-shaped APIs reject empty text blocks, so a content-less thinking turn is thinking only."""
         body = self._transform(
diff --git a/tests/unit/llms/snowflake/test_snowflake_native_endpoints.py b/tests/unit/llms/snowflake/test_snowflake_native_endpoints.py
index 8ddbb7c1a6b..c70128d3225 100644
--- a/tests/unit/llms/snowflake/test_snowflake_native_endpoints.py
+++ b/tests/unit/llms/snowflake/test_snowflake_native_endpoints.py
@@ -20,6 +20,7 @@ from litellm.llms.snowflake.chat.transformation import (
     SnowflakeConfig,
     is_snowflake_claude_model,
 )
+from litellm.llms.snowflake.utils import SnowflakeException
 from litellm.types.utils import ModelResponse
 
 
@@ -342,7 +343,7 @@ class TestAnthropicConfigRequest:
         )
         assert body["system"] == [{"type": "text", "text": "You are helpful."}]
         assert all(m["role"] != "system" for m in body["messages"])
-        assert body["messages"][0] == {"role": "user", "content": "Hello"}
+        assert body["messages"][0] == {"role": "user", "content": [{"type": "text", "text": "Hello"}]}
 
     def test_model_prefix_stripped(self):
         body = self.cfg.transform_request(
@@ -637,7 +638,7 @@ class TestAnthropicMultiTurnToolMessages:
             headers={},
         )
         msgs = body["messages"]
-        assert msgs[0] == {"role": "user", "content": "What's the weather in Paris?"}
+        assert msgs[0] == {"role": "user", "content": [{"type": "text", "text": "What's the weather in Paris?"}]}
 
         assistant_msg = msgs[1]
         assert assistant_msg["role"] == "assistant"
@@ -647,13 +648,14 @@ class TestAnthropicMultiTurnToolMessages:
         assert assistant_msg["content"][0]["name"] == "get_weather"
         assert assistant_msg["content"][0]["input"] == {"city": "Paris"}
 
-        tool_result_msg = msgs[2]
-        assert tool_result_msg["role"] == "user"
-        assert tool_result_msg["content"][0]["type"] == "tool_result"
-        assert tool_result_msg["content"][0]["tool_use_id"] == "call_123"
-        assert tool_result_msg["content"][0]["content"] == "Sunny, 22°C"
-
-        assert msgs[3] == {"role": "user", "content": "Thanks!"}
+        assert msgs[2] == {
+            "role": "user",
+            "content": [
+                {"type": "tool_result", "tool_use_id": "call_123", "content": "Sunny, 22°C"},
+                {"type": "text", "text": "Thanks!"},
+            ],
+        }
+        assert len(msgs) == 3
 
     def test_assistant_with_text_and_tool_calls(self):
         messages = [
@@ -705,7 +707,32 @@ class TestAnthropicMultiTurnToolMessages:
         for msg in body["messages"]:
             assert msg["role"] != "tool"
 
-    def test_malformed_json_in_tool_arguments_handled_gracefully(self):
+    def test_malformed_json_in_tool_arguments_is_rejected_as_bad_request(self):
+        messages = [
+            {"role": "user", "content": "hi"},
+            {
+                "role": "assistant",
+                "content": None,
+                "tool_calls": [
+                    {
+                        "id": "call_bad",
+                        "type": "function",
+                        "function": {"name": "broken_tool", "arguments": "not valid json{{{"},
+                    }
+                ],
+            },
+        ]
+        with pytest.raises(SnowflakeException, match="broken_tool") as excinfo:
+            self.cfg.transform_request(
+                model="snowflake/claude-sonnet-4-5",
+                messages=messages,
+                optional_params={},
+                litellm_params={},
+                headers={},
+            )
+        assert excinfo.value.status_code == 400
+
+    def test_malformed_json_in_tool_arguments_is_dropped_under_drop_params(self):
         messages = [
             {"role": "user", "content": "hi"},
             {
@@ -724,14 +751,12 @@ class TestAnthropicMultiTurnToolMessages:
             model="snowflake/claude-sonnet-4-5",
             messages=messages,
             optional_params={},
-            litellm_params={},
+            litellm_params={"drop_params": True},
             headers={},
         )
-        assistant_msg = body["messages"][1]
-        tool_use_block = assistant_msg["content"][0]
-        assert tool_use_block["type"] == "tool_use"
-        assert tool_use_block["name"] == "broken_tool"
-        assert tool_use_block["input"] == {}
+        assert body["messages"][1]["content"] == [
+            {"type": "tool_use", "id": "call_bad", "name": "broken_tool", "input": {}}
+        ]
 
     def test_non_string_tool_arguments_pass_through(self):
         messages = [
diff --git a/tests/unit/proxy/test_proxy_token_counter.py b/tests/unit/proxy/test_proxy_token_counter.py
index 2f85d1c7516..1a6d105af0f 100644
--- a/tests/unit/proxy/test_proxy_token_counter.py
+++ b/tests/unit/proxy/test_proxy_token_counter.py
@@ -2115,6 +2115,47 @@ async def test_framing_keeps_the_400_for_blocks_the_provider_counter_cannot_conv
     assert "search_result" in raised.value.message
 
 
+@pytest.mark.parametrize(
+    "litellm_params",
+    [
+        {"model": "anthropic/claude-opus-5-5", "api_key": "sk-unused-framed"},
+        {
+            "model": "azure_ai/claude-opus-5-5",
+            "api_key": "sk-unused-framed",
+            "api_base": "https://framed.services.ai.azure.com/anthropic",
+        },
+    ],
+    ids=["anthropic", "azure_ai"],
+)
+@pytest.mark.asyncio
+async def test_framing_keeps_the_400_for_a_text_attachment_the_claude_counter_cannot_decode(
+    monkeypatch: pytest.MonkeyPatch, litellm_params: dict[str, str]
+):
+    monkeypatch.setattr(
+        litellm.proxy.proxy_server,
+        "llm_router",
+        Router(
+            model_list=[
+                {"model_name": "framed", "litellm_params": litellm_params, "model_info": {"token_count_framing": 100}}
+            ]
+        ),
+    )
+    text_attachment: Final = "data:text/plain;charset=bogus-cs;base64," + base64.b64encode(b"hello").decode()
+
+    with pytest.raises(ProxyException) as raised:
+        await count_request_tokens(
+            request=TokenCountRequest(
+                model="framed",
+                messages=[{"role": "user", "content": [{"type": "image_url", "image_url": {"url": text_attachment}}]}],
+            ),
+            call_endpoint=True,
+            messages_format="anthropic",
+        )
+
+    assert raised.value.code == "400"
+    assert "bogus-cs" in raised.value.message
+
+
 @pytest.mark.asyncio
 @pytest.mark.parametrize(
     "unreadable_body",