Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the simple two-parameter input, rich annotations, and an output schema, the description supplies everything extra the agent needs: the grading scale, positional matching rule, sibling-tool routing, and a mandatory output-handling instruction for calculator_url. No critical context is missing.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.