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

No annotations are provided, so the description carries the burden of conveying behavior. It does state the key selection rule—domains proved but not taken—and 'listings' implies a read-only query. However, it doesn't explicitly confirm there are no side effects, whether prior proof is required, or what happens if the passport has no such listings.

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?

The description is a single sentence with no filler or repetition. It is appropriately short, though the phrasing is elliptical ('domains this passport proved') and packs the semantics into a slightly awkward clause rather than a well-structured explanation.

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?

With no output schema, no annotations, and only one short sentence, the description leaves important context implicit. It does not describe the returned listing fields, the meaning of 'taken' relative to claiming, or the exact role of keyId. The core intent is identifiable, but the tool is not fully self-explanatory for an AI 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 coverage is 0%, and the only parameter keyId has no schema description. The phrase 'this passport' gives partial meaning by linking keyId to the passport identity, but it doesn't clearly state that keyId is the passport ID or explain where to obtain it. The description compensates only minimally for the missing schema documentation.

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 indicates that the tool returns listings for domains a passport has proved but not taken/claimed. This gives a clear resource and selection condition, and the phrase 'has not taken' helps distinguish it from claim-related siblings like claim_listings, though it does not name them.

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?

No guidance is given about when to use this tool versus alternatives such as claim_listings, claim_exclusive, or verify_domain. The description implies these are pending or unclaimed listings, but it never tells the agent when to call this instead of a sibling or what prerequisite steps are needed.

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