Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a two-parameter tool with a rich description and an output schema present, all necessary context is covered: prerequisite step, failure mode, retry guidance, and post-success behavior. The annotations already cover idempotency and open-world behavior, so the description does not need to repeat them.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.