fix: Remove status field from toolResult for non-claude 3 models in Bedrock model provider

src/strands/models/bedrock.py

@@ -34,6 +34,11 @@
     "too many total text bytes",
 ]
 
+# Models that should keep tool result status (remove_tool_result_status = False)
+MODELS_KEEP_STATUS = [
+    "anthropic.claude",
+]
+
 T = TypeVar("T", bound=BaseModel)
 
 
@@ -68,6 +73,8 @@ class BedrockConfig(TypedDict, total=False):
             guardrail_redact_output_message: If a Bedrock Output guardrail triggers, replace output with this message.
             max_tokens: Maximum number of tokens to generate in the response
             model_id: The Bedrock model ID (e.g., "us.anthropic.claude-sonnet-4-20250514-v1:0")
+            remove_tool_result_status: Flag to remove status field from tool results.
+                True removes status, False keeps status, "auto" determines based on model_id. Defaults to "auto".
             stop_sequences: List of sequences that will stop generation when encountered
             streaming: Flag to enable/disable streaming. Defaults to True.
             temperature: Controls randomness in generation (higher = more random)
@@ -89,6 +96,7 @@ class BedrockConfig(TypedDict, total=False):
         guardrail_redact_output_message: Optional[str]
         max_tokens: Optional[int]
         model_id: str
+        remove_tool_result_status: Optional[Literal["auto"] | bool]
         stop_sequences: Optional[list[str]]
         streaming: Optional[bool]
         temperature: Optional[float]
@@ -114,7 +122,7 @@ def __init__(
         if region_name and boto_session:
             raise ValueError("Cannot specify both `region_name` and `boto_session`.")
 
-        self.config = BedrockModel.BedrockConfig(model_id=DEFAULT_BEDROCK_MODEL_ID)
+        self.config = BedrockModel.BedrockConfig(model_id=DEFAULT_BEDROCK_MODEL_ID, remove_tool_result_status="auto")
         self.update_config(**model_config)
 
         logger.debug("config=<%s> | initializing", self.config)
@@ -144,6 +152,12 @@ def __init__(
         )
 
         logger.debug("region=<%s> | bedrock client created", self.client.meta.region_name)
+
+        # Resolve "auto" value for remove_tool_result_status
+        if self.config.get("remove_tool_result_status") == "auto":
+            self.config["remove_tool_result_status"] = not any(
+                model in self.config["model_id"] for model in MODELS_KEEP_STATUS
+            )
 
     @override
     def update_config(self, **model_config: Unpack[BedrockConfig]) -> None:  # type: ignore
@@ -153,6 +167,12 @@ def update_config(self, **model_config: Unpack[BedrockConfig]) -> None:  # type:
             **model_config: Configuration overrides.
         """
         self.config.update(model_config)
+
+        # Resolve "auto" value for remove_tool_result_status if needed
+        if self.config.get("remove_tool_result_status") == "auto":
+            self.config["remove_tool_result_status"] = not any(
+                model in self.config["model_id"] for model in MODELS_KEEP_STATUS
+            )
 
     @override
     def get_config(self) -> BedrockConfig:
@@ -276,10 +296,18 @@ def _format_bedrock_messages(self, messages: Messages) -> Messages:
                     # Create a new content block with only the cleaned toolResult
                     tool_result: ToolResult = content_block["toolResult"]
 
-                    # Keep only the required fields for Bedrock
-                    cleaned_tool_result = ToolResult(
-                        content=tool_result["content"], toolUseId=tool_result["toolUseId"], status=tool_result["status"]
-                    )
+                    if self.config.get("remove_tool_result_status") is True:
+                        # Remove status field
+                        cleaned_tool_result = ToolResult(  # type: ignore[typeddict-item]
+                            toolUseId=tool_result["toolUseId"], content=tool_result["content"]
+                        )
+                    else:
+                        # Keep status field
+                        cleaned_tool_result = ToolResult(
+                            content=tool_result["content"],
+                            toolUseId=tool_result["toolUseId"],
+                            status=tool_result["status"],
+                        )
 
                     cleaned_block: ContentBlock = {"toolResult": cleaned_tool_result}
                     cleaned_content.append(cleaned_block)
@@ -290,7 +318,6 @@ def _format_bedrock_messages(self, messages: Messages) -> Messages:
             # Create new message with cleaned content
             cleaned_message: Message = Message(content=cleaned_content, role=message["role"])
             cleaned_messages.append(cleaned_message)
-
         return cleaned_messages
 
     def _has_blocked_guardrail(self, guardrail_data: dict[str, Any]) -> bool:

tests/strands/models/test_bedrock.py

@@ -1211,7 +1211,6 @@ async def test_stream_logging(bedrock_client, model, messages, caplog, alist):
 
 
 def test_format_request_cleans_tool_result_content_blocks(model, model_id):
-    """Test that format_request cleans toolResult blocks by removing extra fields."""
     messages = [
         {
             "role": "user",
@@ -1231,9 +1230,77 @@ def test_format_request_cleans_tool_result_content_blocks(model, model_id):
 
     formatted_request = model.format_request(messages)
 
-    # Verify toolResult only contains allowed fields in the formatted request
     tool_result = formatted_request["messages"][0]["content"][0]["toolResult"]
-    expected = {"content": [{"text": "Tool output"}], "toolUseId": "tool123", "status": "success"}
+    expected = {"toolUseId": "tool123", "content": [{"text": "Tool output"}]}
     assert tool_result == expected
     assert "extraField" not in tool_result
     assert "mcpMetadata" not in tool_result
+    assert "status" not in tool_result
+
+
+def test_format_request_removes_status_field_when_configured(model, model_id):
+    model.update_config(remove_tool_result_status=True)
+
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {
+                    "toolResult": {
+                        "content": [{"text": "Tool output"}],
+                        "toolUseId": "tool123",
+                        "status": "success",
+                    }
+                },
+            ],
+        }
+    ]
+
+    formatted_request = model.format_request(messages)
+
+    tool_result = formatted_request["messages"][0]["content"][0]["toolResult"]
+    expected = {"toolUseId": "tool123", "content": [{"text": "Tool output"}]}
+    assert tool_result == expected
+    assert "status" not in tool_result
+
+
+def test_auto_behavior_anthropic_vs_non_anthropic(bedrock_client):
+    model_anthropic = BedrockModel(model_id="us.anthropic.claude-sonnet-4-20250514-v1:0")
+    assert model_anthropic.get_config()["remove_tool_result_status"] is False
+
+    model_non_anthropic = BedrockModel(model_id="amazon.titan-text-v1")
+    assert model_non_anthropic.get_config()["remove_tool_result_status"] is True
+
+
+def test_explicit_boolean_values_preserved(bedrock_client):
+    model = BedrockModel(model_id="us.anthropic.claude-sonnet-4-20250514-v1:0", remove_tool_result_status=True)
+    assert model.get_config()["remove_tool_result_status"] is True
+
+    model2 = BedrockModel(model_id="amazon.titan-text-v1", remove_tool_result_status=False)
+    assert model2.get_config()["remove_tool_result_status"] is False
+    """Test that format_request keeps status field by default for anthropic.claude models."""
+    # Default model is anthropic.claude, so should keep status
+    model = BedrockModel()
+
+    messages = [
+        {
+            "role": "user",
+            "content": [
+                {
+                    "toolResult": {
+                        "content": [{"text": "Tool output"}],
+                        "toolUseId": "tool123",
+                        "status": "success",
+                    }
+                },
+            ],
+        }
+    ]
+
+    formatted_request = model.format_request(messages)
+
+    # Verify toolResult contains status field by default
+    tool_result = formatted_request["messages"][0]["content"][0]["toolResult"]
+    expected = {"content": [{"text": "Tool output"}], "toolUseId": "tool123", "status": "success"}
+    assert tool_result == expected
+    assert "status" in tool_result