Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple ranking tool, the description conveys the essential operation and return type (rows). However, with no output schema and no annotations, important details such as the default limit value, behavior on non-numeric columns, and explicit read-only status are missing, leaving the agent to infer them.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.