Testing tools with FastMCP >= 2.7: `TypeError: 'FunctionTool' object is not callable`

[amotl]

Problem

When updating to FastMCP 2.7, CI reports this error:

Testing: TypeError: 'FunctionTool' object is not callable

It happens in software tests when calling tools as functions. Apparently, this stopped working in FastMCP. Why?

References

• Update fastmcp requirement from <2.7 to <2.11 #42
• AgentsSDK - @function_tool decorator throws Type Error when used as a regular function for debugging
• Directly calling tool decorated function throws TypeError: 'FunctionTool' object is not callable jlowin/fastmcp#1116

[amotl]

Will be fixed with those patches.

• Dependencies: Allow updating to FastMCP 2.9 #47
• Dependencies: Update to FastMCP 2.10 #48

[amotl]

That's a much better approach.

• Application layout: Refactor core tool functions to separate module #52

In this spirit, testing the tool functions can be left untouched, and upgrading FastMCP is easily possibly without needing to change the semantics of the test suite to learn async capabilities, like exercised in GH-47.

[amotl]

This was resolved per cratedb-mcp 0.0.4.