Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool validates numbers but doesn't describe what validation entails (e.g., format checks, existence verification), whether it's read-only or has side effects, or any performance traits like rate limits. This leaves significant gaps in understanding the tool's behavior beyond the basic input constraint.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.