Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations available, the description carries the full burden. It does disclose a meaningful behavioral trait — only prefixes are returned and secrets are never exposed — which is valuable. However, it says nothing about read-only guarantees, authentication needs, pagination, rate limits, or error behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.