Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden but only states what is checked, not behavioral traits like: whether it returns structured data or plain text, what happens when installations are missing (errors vs warnings), whether it validates executable functionality or just path existence, or if it's safe to run repeatedly.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.