Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable context that the tool returns calculated values plus serialized formulas/inputs, revealing the output composition beyond a simple read, and its intended audit role. This exceeds annotation-only information without contradicting it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.