Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given no annotations, output schema, or parameters, the description carries the sole burden of explaining the tool. It does not define 'semantic flashbacks', the effect of toggling (on/off), or how this interacts with other tools. The description is insufficient for an agent to use the tool correctly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.