Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, openWorld=false, and non-destructive, so the description need not restate those. It adds the useful scoping point that the list is limited to the current deterministic core, but it does not clarify how the optional intent affects behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.