Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations clearly mark the tool as readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds volatility context (data captured every ~10 minutes, window defaults to 24 hours, max 168) and cautions about sample size. However, it does not explain if the percentile is historical real-time or adjusted, nor how funding percent per 8 hours is computed. Still, annotations suffice for safety, and description adds useful nuances.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.