Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds almost nothing beyond restating purpose; it does not disclose result scope, pagination, or what 'feed' returns behaviorally. With annotations carrying the burden, this is a thin but non-contradictory entry.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.