Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations cover the safety profile (not read-only, idempotent, non-destructive, closed-world), and the description adds genuinely new behavioral context: ratings feed a network-wide verifier ranking, and only one rating per task is permitted. It stops short of describing failure behavior when a duplicate rating is attempted or what the call returns.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.