Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple one-parameter destructive tool, the description covers the what, when, and related operations. No output schema is needed for a delete operation, and the usage guidance is sufficient. Minor gap: no mention of behavior for non-existent keys, but idempotentHint covers that implicitly.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.