Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a two-parameter mutation tool, the description covers purpose, side effects, parameters, and return behavior ('Returns success or error'). Since an output schema exists, return details need not be expanded. The only notable gap is explicit routing to sibling tools, which is already accounted for in usage guidelines.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.