Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the tool read-only and non-destructive, so the safety burden is covered. The description adds valuable behavioral context: it is interactive, surveys askable/doable actions, routes to the right tool, and warns about the fee-on-transfer rule.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.