Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden. It clearly states the tool returns URLs, implying a read-only operation with no side effects. While it does not mention potential errors (e.g., server not running), the simplicity of the tool makes this sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.