CedarCopilot/cedar-mail

Branch: staging

fix(mcp): make tool annotations match real behavior (OpenAI app review)

merged#2922CedarCopilot

CedarCopilot wants to merge 2 commits into staging from fix/mcp-tool-annotations-match-behavior

External table filling remains Cedar-only
Libra ran this behavior against the change and confirmed the check detects when it breaks.
Technical evidence
- external table fill keeps open-world false because it returns delegate briefs without external work
Changed code: server.ts.
SQL export advertises its externally accessible result
Libra ran this behavior against the change and confirmed the check detects when it breaks.
Technical evidence
- a SELECT-only run-sql call that exports results is marked non-read-only and open-world
Changed code: server.ts.