Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It only repeats the operation ('list') without any additional context such as whether this is read-only, if it requires specific permissions, how the output is structured, or whether it depends on the current target. The added value over the tool name is negligible.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.