Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple write tool with two fully documented parameters, the description covers the action, identity semantics, and public/logging implications. It does not describe response behavior, but that is not a major gap given the absence of an output schema and the simplicity of the operation.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.