Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already establishes that this is a safe read operation. The description adds value by disclosing the shape of the response, listing protein, W strength, hydration curve, maturation profiles, and description, so the agent knows what data will come back. It does not cover error or not-found behavior, but that is secondary here.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.