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. 'Refresh authentication token' implies a mutation operation that likely requires valid credentials, but the description doesn't specify prerequisites, rate limits, security implications, or what happens to the old token. For a security-sensitive tool with zero annotation coverage, this is inadequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.