Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose two valuable operational facts: this is an x402 paid endpoint and the price ($0.005 on Base). That is genuinely useful. It does not say what happens if tx is omitted, whether payment/auth is required to execute, or what is returned.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.