Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, and the description still adds real value: it confirms the call never mutates state (no apply, no period extension, no new proposal) and gives a recovery pattern for lost responses. It does not say what the response contains or how an unknown/expired review_id behaves, which keeps it below 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.