Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond annotations (readOnly, idempotent, non-destructive), the description adds concrete behavioral details: returns authenticated:true with empty pending[] when connected, and returns connect_url + per-install URLs when credentials are missing. This is useful context, though it does not cover partial connection states.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.