Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds the useful scoping fact that results are per-Agent rather than aggregated, but says nothing about the data window semantics, freshness, or what the dashboard contains.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.