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

With no annotations, the description carries the full burden and does well: it reveals the internal process (RDAP sourcing, anonymous outreach, negotiation), pricing model (commission-only), and a key limitation (GDPR-redacted WHOIS makes many owners unreachable). It also states the required scope 'deals:write.' While it doesn't describe every edge case (e.g., non-response handling), it gives substantial behavioral insight beyond the tool name.

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 three sentences, front-loaded with the main purpose and then expanding into process and caveats. Every clause adds value—no fluff or repetition. It is concise yet information-dense, making efficient use of the format.

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?

Given only 2 parameters and no output schema, the description is quite complete: it covers the action, process, risks, cost structure, and auth requirement. It does not explicitly mention the response format or next steps after negotiation, but the described workflow (accept/counter) implies a result. This is solid for the tool's complexity.

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?

The input schema already provides 100% coverage with descriptions for both 'domain' and 'max_budget.' The description adds no additional parameter-specific details, but the process context (e.g., negotiation, budget ceiling) is implicitly relevant. Since schema coverage is complete, a baseline score 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 clearly states a specific verb-resource-action: 'acquire a specific taken, unlisted domain on your behalf.' It distinguishes from siblings like buy_domain and buy_aftermarket by specifying the domain is taken and unlisted, implying a broker service is needed. The title 'Acquire Domain (Broker)' reinforces the unique purpose.

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 provides clear context for when to use this tool: for taking a 'specific taken, unlisted domain' rather than an available or listed one. It also notes caveats like 'many owners are unreachable' and 'commission-only, no upfront fee,' which help users decide if this approach is appropriate. However, it does not explicitly name alternative tools for other scenarios, so it stops short of full alternative guidance.

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