Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Tool has 2 simple params, 100% schema coverage, and an output schema, so description doesn't need to detail returns. It covers the essential behavioral facts (spend, auth, empty-array). The main gap is the lack of explicit usage guidance relative to sibling extract_* tools, but given the tool's self-evident purpose and full schema coverage, this is reasonably complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.