fix: clarify MCP tool metadata for Glama

[simongonzalezdc]

BLUF

Tightens the CheckYourself MCP tool metadata that Glama scores: explicit auth/network/rate-limit/side-effect language on every tool, and accurate findings input schemas for score/backlog/next.

What changed

• Added a shared MCP description safety footer: no auth, local-only inputs, no network calls, no file modification, no external rate limits.
• Changed findings input schema for score/backlog/next from object-only to object-or-array, matching the existing normalizer behavior.
• Added a regression test that exercises tools/list over stdio.

Verification

• python3 -m unittest discover -s tests -k test_mcp_stdio_exposes_thin_tools
• python3 -m py_compile tools/validate_public.py tools/checkyourself.py tests/test_checkyourself_cli.py
• python3 -m unittest discover -s tests
• python3 tools/validate_public.py
• python3 tools/checkyourself.py describe --format json

---

^{Need help on this PR? Tag /codesmith with what you need. Autofix is disabled.}