Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so safety and repeatability are covered. The description usefully adds which signals are evaluated, but says nothing about whether the rescan is synchronous, slow, or rate-limited — a real concern for a scan-triggering tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.