Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, covering the safety profile. The description adds that it returns real-time data including specific fields, which is useful but doesn't go much beyond annotations. It could mention rate limits or that data is for futures symbols, but the annotations carry the safety burden, so adds a bit of value for the return context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.