Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description only needs extra behavioral context. It adds valuable behavior: returns 'no road cameras' outside the covered area, includes a live image URL for each camera, and names the data sources. This goes beyond the structured annotations without contradicting them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.