Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, and it discloses that the tool returns both a result and its legal basis. However, it says nothing about behavior on an invalid or unknown slug, whether args is optional, or any error handling — meaningful gaps for a tool with no annotation coverage.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.