Return CallToolResult from convert_result instead of a tuple#2175
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Return CallToolResult from convert_result instead of a tuple#2175
CallToolResult from convert_result instead of a tuple#2175Conversation
`convert_result()` was returning a bare `(unstructured, structured)` tuple when an output schema was present, leaking an internal detail through `MCPServer.call_tool`'s public API. The declared return type `Sequence[ContentBlock] | dict[str, Any]` was also wrong - the `dict` branch was unreachable. Now `convert_result()` returns a `CallToolResult` directly, and `MCPServer.call_tool` is typed as `CallToolResult | Sequence[ContentBlock]`. The tuple-unpacking and dead `dict` branches in `_handle_call_tool` are removed. Github-Issue: #1251
Kludex
commented
Feb 28, 2026
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Summary
convert_result()now returns aCallToolResultdirectly when structured output is present, instead of a bare(unstructured, structured)tuple that leaked through the public API.MCPServer.call_toolreturn type corrected fromSequence[ContentBlock] | dict[str, Any]toCallToolResult | Sequence[ContentBlock].dictbranches from_handle_call_tool.Closes #1251
Test plan
test_func_metadata.py,test_tool_manager.py, andtest_server.pyupdated and passing (170 tests)ruff checkandpyrightclean on all changed files