Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds substantial extra context beyond them: ordering by id, no pagination, empty-list semantics, and the important caveat that 'approval is an internal source policy, not independent factual verification.' That last point is a genuine behavioral disclosure an agent could not get from the schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.