Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a retrieval tool with pagination parameters, undocumented sibling differentiation, no output schema, and no annotations, the description is too thin. It doesn't explain pagination semantics, comment ordering, the relationship between start/start_id, or how this differs from other comment-getting tools. Given the 3 parameters and complex sibling landscape, it should do substantially more.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.