Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already cover the safe read-only, idempotent, non-destructive profile, so the description's added 'newest first' ordering and the semantic that it lists owned stories carry useful extra information. It adds behavioral ordering context beyond the annotations without repeating them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.