Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. 'Create a new lead list' implies a write/mutation operation, but it doesn't disclose permissions needed, whether the operation is idempotent, what happens on failure, or what the response contains. For a creation tool with zero annotation coverage, this leaves significant behavioral gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.