Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety profile is covered and the bar is lower. However, the description adds nothing behavioral: it doesn't indicate what corpus is searched, how results are ordered, or that pagination exists. OpenWorld suggests non-exhaustive external results, which the description never reinforces.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.