Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It discloses the cost ($0.09 via x402), the legal/opt-in nature, and the output types, which is useful. However, it omits error handling, rate limits, or prerequisites beyond the payment payload, leaving notable gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.