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. It correctly indicates a read operation ('return') but omits details like potential performance impact, whether the data is fresh, or if authentication is needed. The simplicity of a no-parameter list-all makes this acceptable.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.