Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It only states a vague action ('get current Bitcoin price and market data') without mentioning that it is read-only, what data fields are included, or any rate limits. The agent lacks essential behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.