diff --git a/litellm/llms/anthropic/common_utils.py b/litellm/llms/anthropic/common_utils.py
index 74f40b52f39..9a58d85238a 100644
--- a/litellm/llms/anthropic/common_utils.py
+++ b/litellm/llms/anthropic/common_utils.py
@@ -1792,7 +1792,7 @@ def encode_thought_signature_for_anthropic_tool_id(signature: str) -> str:
 
 def decode_thought_signature_from_anthropic_tool_id(encoded: str) -> str:
     """Inverse of ``encode_thought_signature_for_anthropic_tool_id``."""
-    pad = (-len(encoded)) % 4
+    pad: Final = (-len(encoded)) % 4
     return base64.urlsafe_b64decode(encoded + ("=" * pad)).decode("utf-8")
 
 
@@ -1806,7 +1806,7 @@ def format_anthropic_tool_use_id_with_signature(raw_id: str, thought_signature:
     signature after ``__thought__`` lets those clients round-trip the real
     signature the same way OpenAI-compatible clients do via ``tool_calls[].id``.
     """
-    base_id = normalize_anthropic_tool_use_id(raw_id)
+    base_id: Final = normalize_anthropic_tool_use_id(raw_id)
     if not thought_signature:
         return base_id
     return f"{base_id}{THOUGHT_SIGNATURE_SEPARATOR}{encode_thought_signature_for_anthropic_tool_id(thought_signature)}"
diff --git a/litellm/llms/anthropic/pass_through/adapters/transformation.py b/litellm/llms/anthropic/pass_through/adapters/transformation.py
index c0fbea3414b..459469cda5c 100644
--- a/litellm/llms/anthropic/pass_through/adapters/transformation.py
+++ b/litellm/llms/anthropic/pass_through/adapters/transformation.py
@@ -367,19 +367,19 @@ class LiteLLMAnthropicMessagesAdapter:
         """
         fields: Final = _optional_attr(tool_call, "provider_specific_fields")
         if fields:
-            signature = _thought_signature(fields)
+            signature: Final = _thought_signature(fields)
             if signature:
                 return signature
 
         function_fields: Final = _optional_attr(_optional_attr(tool_call, "function"), "provider_specific_fields")
         if function_fields:
-            signature = _thought_signature(function_fields)
-            if signature:
-                return signature
+            function_signature: Final = _thought_signature(function_fields)
+            if function_signature:
+                return function_signature
 
         raw_id: Final = _optional_attr(tool_call, "id")
         if isinstance(raw_id, str) and THOUGHT_SIGNATURE_SEPARATOR in raw_id:
-            parts = raw_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)
+            parts: Final = raw_id.split(THOUGHT_SIGNATURE_SEPARATOR, 1)
             if len(parts) == 2 and parts[1]:
                 return parts[1]