From 779006fdf939f57030dbe5341f6d090eeb726387 Mon Sep 17 00:00:00 2001
From: mateo-berri <277851410+mateo-berri@users.noreply.github.com>
Date: Mon, 12 Oct 2026 12:59:20 -0700
Subject: [PATCH] fix(anthropic): drop the json tool description that makes
 sonnet-5 omit required keys

---
 litellm/constants.py                                     | 3 ---
 litellm/llms/anthropic/chat/transformation.py            | 2 --
 .../anthropic/chat/test_anthropic_chat_transformation.py | 1 -
 .../chat/test_databricks_chat_transformation.py          | 2 --
 tests/unit/llms/vertex_ai/test_vertex.py                 | 9 +--------
 5 files changed, 1 insertion(+), 16 deletions(-)

diff --git a/litellm/constants.py b/litellm/constants.py
index 88c2123476c..38d16d61d7b 100644
--- a/litellm/constants.py
+++ b/litellm/constants.py
@@ -1586,9 +1586,6 @@ OPENAI_FINISH_REASONS: Final = [
 ]
 HUMANLOOP_PROMPT_CACHE_TTL_SECONDS: Final = int(os.getenv("HUMANLOOP_PROMPT_CACHE_TTL_SECONDS", 60))  # 1 minute
 RESPONSE_FORMAT_TOOL_NAME = "json_tool_call"  # default tool name used when converting response format to tool call
-RESPONSE_FORMAT_TOOL_DESCRIPTION: Final = (
-    "Return the final answer as this structured object, filling every required field."
-)
 
 ########################### Logging Callback Constants ###########################
 AZURE_STORAGE_MSFT_VERSION: Final = "2019-07-07"
diff --git a/litellm/llms/anthropic/chat/transformation.py b/litellm/llms/anthropic/chat/transformation.py
index fefa40bd91f..0aeef3d06e6 100644
--- a/litellm/llms/anthropic/chat/transformation.py
+++ b/litellm/llms/anthropic/chat/transformation.py
@@ -20,7 +20,6 @@ from litellm.constants import (
     DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_MINIMAL_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_XHIGH_THINKING_BUDGET,
-    RESPONSE_FORMAT_TOOL_DESCRIPTION,
     RESPONSE_FORMAT_TOOL_NAME,
 )
 from litellm.litellm_core_utils.core_helpers import map_finish_reason
@@ -1755,7 +1754,6 @@ class AnthropicConfig(AnthropicModelInfo, BaseConfig):
 
         _tool: Final = AnthropicMessagesTool(
             name=RESPONSE_FORMAT_TOOL_NAME,
-            description=RESPONSE_FORMAT_TOOL_DESCRIPTION,
             input_schema=_input_schema,
         )
         return _tool
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 4d46c1a30c5..4e8971c1524 100644
--- a/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py
+++ b/tests/unit/llms/anthropic/chat/test_anthropic_chat_transformation.py
@@ -7498,7 +7498,6 @@ def test_vertex_claude_tool_emulated_response_format_returns_the_object_the_mode
     )
     json_tool = next(tool for tool in request["tools"] if tool["name"] == RESPONSE_FORMAT_TOOL_NAME)
     assert json_tool["input_schema"]["required"] == ["tier", "summary"]
-    assert json_tool["description"]
     assert "output_format" not in request
     assert "output_config" not in request
     completion_response = {
diff --git a/tests/unit/llms/databricks/chat/test_databricks_chat_transformation.py b/tests/unit/llms/databricks/chat/test_databricks_chat_transformation.py
index c66efe21749..c6e0ecd2b41 100644
--- a/tests/unit/llms/databricks/chat/test_databricks_chat_transformation.py
+++ b/tests/unit/llms/databricks/chat/test_databricks_chat_transformation.py
@@ -16,7 +16,6 @@ from litellm.constants import (
     DEFAULT_REASONING_EFFORT_HIGH_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_LOW_THINKING_BUDGET,
     DEFAULT_REASONING_EFFORT_MEDIUM_THINKING_BUDGET,
-    RESPONSE_FORMAT_TOOL_DESCRIPTION,
 )
 from litellm.llms.custom_httpx.http_handler import AsyncHTTPHandler, HTTPHandler
 from litellm.llms.databricks.chat.transformation import (
@@ -2144,7 +2143,6 @@ def test_databricks_claude_json_schema_preserves_refs_in_tool_parameters() -> No
             "function": {
                 "name": "json_tool_call",
                 "parameters": JSON_SCHEMA_RESPONSE_FORMAT["json_schema"]["schema"],
-                "description": RESPONSE_FORMAT_TOOL_DESCRIPTION,
             },
         }
     ]
diff --git a/tests/unit/llms/vertex_ai/test_vertex.py b/tests/unit/llms/vertex_ai/test_vertex.py
index c5aaa010a96..044a07859f9 100644
--- a/tests/unit/llms/vertex_ai/test_vertex.py
+++ b/tests/unit/llms/vertex_ai/test_vertex.py
@@ -22,7 +22,6 @@ import pytest
 
 import litellm
 from litellm import Router, get_optional_params
-from litellm.constants import RESPONSE_FORMAT_TOOL_DESCRIPTION
 from litellm.llms.vertex_ai.gemini.transformation import _process_gemini_media
 from litellm.types.llms.vertex_ai import BlobType
 
@@ -2693,13 +2692,7 @@ def test_gemini_pro_json_schema_args_sent_httpx(
     request_body: Final = json.loads(route.calls[0].request.content)
     if "claude" in model:
         assert request_body["tool_choice"] == {"type": "tool", "name": "json_tool_call"}
-        assert request_body["tools"] == [
-            {
-                "name": "json_tool_call",
-                "description": RESPONSE_FORMAT_TOOL_DESCRIPTION,
-                "input_schema": _RECIPES_SCHEMA,
-            }
-        ]
+        assert request_body["tools"] == [{"name": "json_tool_call", "input_schema": _RECIPES_SCHEMA}]
     else:
         assert request_body["generationConfig"]["response_mime_type"] == "application/json"
         assert request_body["generationConfig"]["response_json_schema"] == _RECIPES_SCHEMA