Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a parameter-less tool with an output schema, the description is minimally adequate, but it lacks contextual details such as when redo is available (e.g., after an undo), what happens if the redo stack is empty, and any error behavior. Since the tool is simple, a score of 3 reflects that it is usable but has clear gaps in behavioral context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.