Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the read-only and idempotent nature, but the description adds substantial behavioral context: a 50-entry limit, newest-first ordering, the fact that each snapshot holds content from before its entry, and that restoration happens outside the tool within the plan's restore window.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.