Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple delete-by-key tool with one required parameter and no output schema, the description is complete. Annotations cover safety (destructive, idempotent), and the description provides usage context. It could mention idempotency behavior explicitly, but annotations already cover that, so this is sufficient.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.