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. 'List backups' implies a read-only operation, but it doesn't specify if it requires authentication, rate limits, pagination, or what the output format looks like (e.g., list of backup names or detailed metadata). This leaves significant gaps for a tool with potential complexity.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.