Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, indicating a safe, repeatable operation. The description adds no behavioral context beyond this, such as what 'entities' refer to (faces, edges), how angles are calculated, or any limitations. It doesn't contradict annotations, but offers minimal additional insight.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.