Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations are present (readOnlyHint=false, openWorldHint=true, destructiveHint=false), and the description adds cost ('~$0.005') and source (CoinGecko). However, it doesn't disclose data freshness intervals, rate limits, or the oddity that readOnlyHint=false for a read-only operation. The description is minimal but not contradictory.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.