[Junpei Zhang (pei711)]

Why are these changes needed?

FunctionTool.run currently sends every validated argument as a keyword. Python rejects keyword calls for parameters declared positional-only, so otherwise valid run_json() calls raise TypeError. Preserve each parameter's calling convention for both sync and async functions, including positional-only cancellation-token injection.

Related issue number

Closes #8319

Checks

• I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md to build and test documentation locally.
• I've added tests (if relevant) corresponding to the changes introduced in this PR.
• I've made sure all auto checks have passed.

Local verification: autogen-core/tests/test_tools.py (43 passed), Ruff check, Ruff format check, and git diff --check.

[Junpei Zhang (pei711)]

@microsoft-github-policy-service agree