Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple tool with one parameter, the description is fully sufficient. It covers what, when, prerequisites, cost, and behavioral guarantees. No output schema exists, but the tool is a mutation, and the description does not need to explain return values. Siblings are acknowledged via the skip contrast, making it contextually complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.