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 and no output schema, the description provides adequate context: what it returns (A-E grade), how it's derived (from status, charges, filings), and its limitations (heuristic, not financial advice). It could mention the output structure more explicitly but remains reasonably complete.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.