Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish read-only, idempotent, and non-destructive behavior. The description adds meaningful behavioral context beyond that: the exact fields returned, the explicit missing-mint list, the per-call cost, and byte-identical equivalence to a REST endpoint. No contradictions with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.