Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description still adds real behavioral context: it reads current recommendations only and returns no raw measures, which tells the agent what it will and will not get back. It does not, however, discuss latency, auth scoping, or how deep the provenance chain goes.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.