Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a one-parameter, read-only snapshot tool whose safety is already covered by annotations, the description covers the data returned, input format, output format, and cost — most of what an agent needs. The minor gap is the underspecified scope of 'most recent filings' (how many, which form types, what period), which matters more because no output schema exists to clarify it.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.