Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already convey readOnly, openWorld, idempotent, and non-destructive behavior, so the description carries less burden. It adds that the tool returns state names and abbreviations and covers all U.S. states, which is useful but not deeply behavioral. No contradictions with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.