Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Goes well beyond the annotations (destructiveHint=true, openWorldHint=true) by disclosing cascade effects: keywords leave list_websites, active keywords free plan slots, pending keywords may auto-activate, and searches/ranking checks get queued. It also discloses irreversibility ('no restore tool') plus the recovery workaround (create_website with the same URL), and the return/error contract (404 if ID unknown).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.