Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds value beyond that by specifying the return shape: a Markdown list with each gap's title, severity, summary, and suggested file paths. It does not go into pagination or the fallback repository-selection behavior, but that is covered by the schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, each earning its place: the first states the tool's purpose, the second describes the return value, and the third names the correct alternatives. No repetition of schema or annotation data.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The tool has few parameters and no output schema, so the description's explanation of the Markdown output is sufficient. It also provides sibling differentiation and confirms no side effects, making a complete decision picture for the agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the parameters are already well-documented. The tool description does not add new parameter-level semantics beyond mentioning severity in the output summary, so the baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb-resource pair: "List the unresolved documentation gaps Moxie found - areas of the codebase that lack docs." It also distinguishes itself from the closest siblings by stating "This is gaps only" and naming get_documentation_opportunities and get_doc_impact as alternatives.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives explicit guidance on when to use the tool versus alternatives: use get_documentation_opportunities for the full prioritized work queue and get_doc_impact to scope gaps to files being edited. This is an explicit when/when-not statement.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.