Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover safety (readOnlyHint=true, idempotentHint=true, destructiveHint=false), so the bar is lower. The description nonetheless adds real behavioral context beyond them: ordering (reverse chronological), pagination mechanics (cursor), and the fields returned. It omits any page-size limit or what the cursor's absence means.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.