Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds genuine behavioral context beyond that: array results are capped at 20 items, text values are bounded, and freshness metadata is included. It says nothing about permissions or error behavior, so it adds useful but partial context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.