diff --git a/src/fastmcp/tools/tool_transform.py b/src/fastmcp/tools/tool_transform.py index aca45d8f8..5f40b91bf 100644 --- a/src/fastmcp/tools/tool_transform.py +++ b/src/fastmcp/tools/tool_transform.py @@ -445,7 +445,7 @@ class TransformedTool(Tool): if unknown_args: raise ValueError( f"Unknown arguments in transform_args: {', '.join(sorted(unknown_args))}. " - f"Parent tool has: {', '.join(sorted(parent_params))}" + f"Parent tool `{tool.name}` has: {', '.join(sorted(parent_params))}" ) # Always create the forwarding transform diff --git a/tests/tools/test_tool_transform.py b/tests/tools/test_tool_transform.py index e1f062394..e65154ec8 100644 --- a/tests/tools/test_tool_transform.py +++ b/tests/tools/test_tool_transform.py @@ -404,11 +404,13 @@ def test_transform_args_validation_unknown_arg(add_tool): """Test that transform_args with unknown arguments raises ValueError.""" with pytest.raises( ValueError, match="Unknown arguments in transform_args: unknown_param" - ): + ) as exc_info: Tool.from_tool( add_tool, transform_args={"unknown_param": ArgTransform(name="new_name")} ) + assert "`add`" in str(exc_info.value) + def test_transform_args_creates_duplicate_names(add_tool): """Test that transform_args creating duplicate parameter names raises ValueError."""