Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is fully covered without the description. The description adds nothing beyond that — no note on what a timeline entry contains, whether the id is a UUID or slug, or what happens on a missing id. It does not contradict the annotations, but it contributes zero behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.