Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description discloses the $0.25 USDC cost, which is a meaningful behavioral trait, but with no annotations it carries the full burden of behavioral disclosure. It does not explain the output structure, whether the price data is a time series or snapshot, or how the four components are combined. Significant behavioral details remain hidden.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.