Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds real behavioral context beyond that: newest-first ordering, the default 30-day window and what lifts it, and the shape of each entry (day, note, recipe summary with source link).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.