Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new behavior: results are committed-only, ordered newest first, and paged backwards via a revision cursor. It says nothing about rate limits, page-size behavior, or what happens at the end of history.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.