Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the tool is clearly safe to call. The description adds the time dimension ('current') and the domain ('crypto'), but does not disclose if results are paginated, cached, or if there's any rate limiting. Since annotations cover the key safety info, the description gets a 3 for adding some context without contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.