Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, closed-world behavior, so safety semantics are covered. The description adds that this returns a list with specific fields and that a locale affects the returned body, which is useful context beyond the annotations, though it doesn't discuss ordering or pagination.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.