Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It explicitly discloses that this is a FREE read operation, signaling non-destructive behavior. It does not mention rate limits or auth requirements, but for a simple read tool the key behavioral trait is covered.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.