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), and the description goes well past them: it discloses the NOT_FOUND threshold, the private-colony exclusion, the subdomain-to-registrable-domain rollup, and the rule that agent and human impressions are separate units.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.