feat: add include_response_info parameter to control response documentation

Add parameter to disable automatic response info in tool descriptions.
Defaults to True for backward compatibility.
Resolves #212

Author: Edison-A-N

fastapi_mcp/openapi/convert.py

@@ -18,6 +18,7 @@ def convert_openapi_to_mcp_tools(
     openapi_schema: Dict[str, Any],
     describe_all_responses: bool = False,
     describe_full_response_schema: bool = False,
+    include_response_info: bool = True,
 ) -> Tuple[List[types.Tool], Dict[str, Dict[str, Any]]]:
     """
     Convert OpenAPI operations to MCP tools.
@@ -26,6 +27,7 @@ def convert_openapi_to_mcp_tools(
         openapi_schema: The OpenAPI schema
         describe_all_responses: Whether to include all possible response schemas in tool descriptions
         describe_full_response_schema: Whether to include full response schema in tool descriptions
+        include_response_info: Whether to include response information in tool descriptions
 
     Returns:
         A tuple containing:
@@ -70,7 +72,7 @@ def convert_openapi_to_mcp_tools(
 
             # Add response information to the description
             responses = operation.get("responses", {})
-            if responses:
+            if responses and include_response_info:
                 response_info = "\n\n### Responses:\n"
 
                 # Find the success response

fastapi_mcp/server.py

@@ -46,6 +46,10 @@ def __init__(
             bool,
             Doc("Whether to include full json schema for responses in tool descriptions"),
         ] = False,
+        include_response_info: Annotated[
+            bool,
+            Doc("Whether to include response information in tool descriptions"),
+        ] = True,
         http_client: Annotated[
             Optional[httpx.AsyncClient],
             Doc(
@@ -103,6 +107,7 @@ def __init__(
         self._base_url = "http://apiserver"
         self._describe_all_responses = describe_all_responses
         self._describe_full_response_schema = describe_full_response_schema
+        self._include_response_info = include_response_info
         self._include_operations = include_operations
         self._exclude_operations = exclude_operations
         self._include_tags = include_tags
@@ -136,6 +141,7 @@ def setup_server(self) -> None:
             openapi_schema,
             describe_all_responses=self._describe_all_responses,
             describe_full_response_schema=self._describe_full_response_schema,
+            include_response_info=self._include_response_info,
         )
 
         # Filter tools based on operation IDs and tags

tests/test_configuration.py

@@ -581,3 +581,84 @@ async def empty_tags():
     exclude_tags_mcp = FastApiMCP(app, exclude_tags=["items"])
     assert len(exclude_tags_mcp.tools) == 1
     assert {tool.name for tool in exclude_tags_mcp.tools} == {"empty_tags"}
+
+
+def test_include_response_info_default_behavior(simple_fastapi_app: FastAPI):
+    """Test the default behavior of include_response_info parameter."""
+    mcp_server = FastApiMCP(simple_fastapi_app)
+
+    # Check default value
+    assert mcp_server._include_response_info is True
+
+    # Check that response information is included by default
+    for tool in mcp_server.tools:
+        assert tool.description is not None
+        if tool.name == "raise_error":
+            pass
+        elif tool.name != "delete_item":
+            assert "### Responses:" in tool.description, "Response section should be present"
+            assert "**200**" in tool.description, "200 status code should be present"
+            assert "**Example Response:**" in tool.description, "Example response should be present"
+        else:
+            # The delete endpoint returns 204 with no response body
+            assert "### Responses:" in tool.description, "Response section should be present"
+            assert "**204**" in tool.description, "204 status code should be present"
+
+
+def test_include_response_info_false_simple_app(simple_fastapi_app: FastAPI):
+    """Test include_response_info=False with the simple app."""
+    mcp_server = FastApiMCP(simple_fastapi_app, include_response_info=False)
+
+    # Check that response information is excluded
+    for tool in mcp_server.tools:
+        assert tool.description is not None
+        assert "### Responses:" not in tool.description, "Response section should not be present"
+        assert "**200**" not in tool.description, "200 status code should not be present"
+        assert "**204**" not in tool.description, "204 status code should not be present"
+        assert "**Example Response:**" not in tool.description, "Example response should not be present"
+        assert "**Output Schema:**" not in tool.description, "Output schema should not be present"
+
+        # Basic tool information should still be present
+        if tool.name == "list_items":
+            assert "List all items" in tool.description
+        elif tool.name == "get_item":
+            assert "Get a specific item" in tool.description
+        elif tool.name == "create_item":
+            assert "Create a new item" in tool.description
+
+
+def test_include_response_info_combined_with_other_options(simple_fastapi_app: FastAPI):
+    """Test include_response_info combined with other response-related options."""
+    # Test with include_response_info=False and describe_all_responses=True
+    mcp_server = FastApiMCP(
+        simple_fastapi_app,
+        include_response_info=False,
+        describe_all_responses=True,
+        describe_full_response_schema=True,
+    )
+
+    # Even with describe_all_responses=True and describe_full_response_schema=True,
+    # response information should be excluded when include_response_info=False
+    for tool in mcp_server.tools:
+        assert tool.description is not None
+        assert "### Responses:" not in tool.description, "Response section should not be present"
+        assert "**Example Response:**" not in tool.description, "Example response should not be present"
+        assert "**Output Schema:**" not in tool.description, "Output schema should not be present"
+
+
+def test_include_response_info_true_explicit(simple_fastapi_app: FastAPI):
+    """Test include_response_info=True explicitly."""
+    mcp_server = FastApiMCP(simple_fastapi_app, include_response_info=True)
+
+    # Check that response information is included
+    for tool in mcp_server.tools:
+        assert tool.description is not None
+        if tool.name == "raise_error":
+            pass
+        elif tool.name != "delete_item":
+            assert "### Responses:" in tool.description, "Response section should be present"
+            assert "**200**" in tool.description, "200 status code should be present"
+            assert "**Example Response:**" in tool.description, "Example response should be present"
+        else:
+            assert "### Responses:" in tool.description, "Response section should be present"
+            assert "**204**" in tool.description, "204 status code should be present"