Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), yet the description goes further and discloses the actual behavior: a free sample is returned here with a paid URL and pay steps, no charge at this call, and the full result costs $17 Base USDC via x402. That pricing/payment flow is exactly the context an agent cannot get from annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.