Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the write/destructive, non-idempotent, open-world profile, so the bar is lower; the description still adds real substance by disclosing the side effects (office notification, transactional SMS acknowledgment) and clarifying that a lead is not an appointment. It does not address duplicate submissions or what data is persisted, which is the only remaining gap.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.