test: add tests for either FastMCP implementation

[constantinius]

Issues

Closes https://linear.app/getsentry/issue/TET-1329/fastmcp-tests

Reminders

• Please add tests to validate your changes, and lint your code using tox -e linters.
• Add GH Issue ID & Linear ID (if applicable)
• PR title should use conventional commit style (feat:, fix:, ref:, meta:)
• For external contributors: CONTRIBUTING.md, Sentry SDK development docs, Discord community

[linear]

TET-1329 FastMCP: tests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.04%. Comparing base (9b497d7) to head (86c5f20).
⚠️ Report is 13 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5075      +/-   ##
==========================================
+ Coverage   83.96%   84.04%   +0.08%     
==========================================
  Files         179      180       +1     
  Lines       17951    18030      +79     
  Branches     3194     3209      +15     
==========================================
+ Hits        15073    15154      +81     
+ Misses       1906     1899       -7     
- Partials      972      977       +5     

see 21 files with indirect coverage changes

[sentry]

Bug: The fastmcp tox environment's TESTPATH in tox.ini line 808 points to a non-existent directory, preventing test discovery.
_{Severity: HIGH | Confidence: 1.00}

🔍 Detailed Analysis

The fastmcp tox environment's TESTPATH is incorrectly configured in tox.ini at line 808. It points to tests/integrations/fastmcp, a non-existent directory. The actual test file, test_fastmcp.py, resides in tests/integrations/mcp. This misconfiguration prevents pytest from discovering and executing any tests for the fastmcp integration suite, resulting in a silent failure where no tests are run.

💡 Suggested Fix

Update tox.ini line 808 to set fastmcp: TESTPATH=tests/integrations/mcp. This will correctly direct pytest to the location of the fastmcp integration tests.

🤖 Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.

Location: tox.ini#L808

Potential issue: The `fastmcp` tox environment's `TESTPATH` is incorrectly configured in
`tox.ini` at line 808. It points to `tests/integrations/fastmcp`, a non-existent
directory. The actual test file, `test_fastmcp.py`, resides in `tests/integrations/mcp`.
This misconfiguration prevents `pytest` from discovering and executing any tests for the
`fastmcp` integration suite, resulting in a silent failure where no tests are run.

_{Did we get this right? 👍 / 👎 to inform future reviews.}

[alexander-alderman-webb]

I would put the new tests in a new tests/integrations/fastmcp directory.

If we changed the TESTPATH of the fastmcp entry to be tests/integrations/mcp, then we would be running mcp tests twice in our CI.

[alexander-alderman-webb]

There are CI failures due to version bumps picked up by generate_tox.py. We're fixing them

• tests(huggingface): Avoid None version #5083
• fix(pydantic-ai): Do not fail on new ToolManager._call_tool() parameters #5084