Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare a safe read (readOnly, idempotent, non-destructive), so the main added value is the disclosed mode switch: before insights exist (aggregated=false) it returns transcript excerpts rather than summary/themes. That is genuine behavioral context an agent can't get from annotations, though pagination or size limits are not addressed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.