domain-check

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

With no annotations, the description carries the burden and does well by disclosing rate limiting, no-key access, report URL generation, and commission behavior. It does not explicitly state read-only semantics or failure handling, but the 'check' verb and operational constraints provide a solid transparency baseline.

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, each earning its place: core behavior, operational constraints, and optional parameter explanation. It is front-loaded with the primary purpose and contains no redundant or promotional filler.

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?

Despite lacking an output schema, the description explains what the tool checks, the grading scale, the shareable report URL, and rate-limit/auth constraints. It is complete for a simple check tool, though it could optionally clarify the exact return format or provide an example.

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 schema already covers both parameters (100% coverage), and the description adds meaning for 'ref' by explaining the referral/commission relationship. For 'domain', the description reinforces its meaning as the subject of the mail-deliverability check, exceeding the baseline schema-only case.

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 states a specific action ('Check whether anyone can spoof mail from a domain') with detailed scope (SPF, DMARC, MX, DKIM) and output (A-F grade, shareable report URL). It clearly distinguishes itself from siblings like list_services and partner_program by describing a domain-specific diagnostic operation.

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 useful context like 'Free, no key, rate-limited per caller' and explains the optional referral code, implying when to use it. However, it does not explicitly state when to use this tool over alternatives or mention any exclusions, so usage guidance remains implied rather than explicit.

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

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

With no annotations, the description carries the burden. It explains the tool provides a paid catalogue and instructs users to include a referral code in order URLs for compensation, adding behavioral context beyond the name. However, it doesn't disclose potential side effects or limitations, though none are apparent for a listing tool.

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 two sentences, front-loaded with the core purpose, and the second sentence provides an actionable detail. No fluff.

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?

For a no-parameter list tool, the description fully explains what data is returned (coverage, cost, order URL) and includes the key referral instruction. Even without an output schema, the description is sufficient.

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 tool has zero parameters, and schema coverage is 100% (vacuously), so the baseline of 4 applies. The description adds some context about the referral code but no parameter-specific details are needed.

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 the tool lists paid services with coverage, cost, and order URLs. It uses a specific verb ('list') and resource ('services'), and the title reinforces the purpose. It distinguishes itself from siblings by focusing on the paid catalogue.

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 implies the tool is used to browse the paid catalogue, but it does not explicitly state when to use it or mention alternatives. No exclusions or when-not guidance.

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

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

With no annotations, the description must carry the burden. It clearly conveys that this is an informational tool about how the partner program works, not a tool that actually registers or pays. However, it could be more explicit about being read-only and not invoking real-world actions.

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, well-structured sentence that front-loads the core value proposition and lists concrete topics. Every part contributes meaning without redundancy.

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?

For a simple informational tool with no input/output schema, the description covers the essential points. It could be slightly improved by explicitly stating it returns a guide/reference and has no side effects, but it is largely complete.

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 tool has zero parameters, so the baseline is 4. The description compensates by detailing the content areas, but there is no additional parameter-related information to add.

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 the tool's purpose: explaining how an agent earns money with the Guild. It lists specific topics covered (commission rates, settled orders, registration, payment), making it distinct from sibling tools like check_domain and list_services.

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 implicitly indicates when to use this tool: when an agent needs to understand commission earnings and related processes. While it doesn't explicitly name exclusions or alternatives, the scope is clear and distinct from siblings.

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