Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover read-only, idempotent, non-destructive and closed-world behavior, so the bar is lower; the description still adds useful guarantees ('never collects personal data or creates an order') and a scope qualifier ('verified public'). It says nothing about response shape, but an output schema exists to carry that.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.