Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotation readOnlyHint=true already indicates a safe read operation, and the description 'List routes' aligns with that. However, the description adds no additional behavioral context such as what routes are returned, whether there is pagination, or any prerequisites.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.