fix(mcp): Handle None arguments in tool and prompt handlers

[alexander-alderman-webb]

Description

Just following the types, arguments can be None. For example:

https://github.com/modelcontextprotocol/python-sdk/blob/d060b36e1d095ef6e93e07ba5d59bb69b2ad449a/src/mcp-types/mcp_types/_types.py#L1449-L1453

The prompt case is recorded in the reported issue.

Issues

Closes #7374

Reminders

• Please add tests to validate your changes, and lint your code using uv run ruff.
• 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

[github-actions]

Codecov Results 📊

✅ 130572 passed | ⏭️ 7110 skipped | Total: 137682 | Pass Rate: 94.84% | Execution Time: 472m 22s

📊 Comparison with Base Branch

Metric	Change
Total Tests	—
Passed Tests	📈 +1
Failed Tests	📉 -1
Skipped Tests	—

➖ Removed Tests (1)

View removed tests

• test_cache_spans_decorator[True]
  • File: tests.integrations.django.test_cache_module

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 2509 uncovered lines.
❌ Project coverage is 90.24%. Comparing base (a5e2c60) to head (feea878).

Files with missing lines (1)

File	Patch %	Lines
sentry_sdk/integrations/mcp.py	100.00%	⚠️ 2 partials

Coverage diff

@@            Coverage Diff             @@
##        master       #PR       +/-##
==========================================
- Coverage    90.27%    90.24%    -0.03%
==========================================
  Files          193       193         —
  Lines        25713     25713         —
  Branches      9494      9494         —
==========================================
+ Hits         23211     23204        -7
- Misses        2502      2509        +7
- Partials      1432      1432         —

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