Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behaviors. It mentions the tool is paid ($0.002) and returns specific data fields, but lacks details on error handling, rate limits, or what happens with invalid addresses. Knowledge of payment is useful, but incomplete for a production tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.