Email authentication posture for a domain: DMARC + SPF records fetched, parsed, scored 0-100, with findings and fix recommendations. Paid per call: $0.01 in USDC via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Domain to analyse (path parameter) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full burden. It discloses that records are fetched, parsed, scored, and that recommendations are provided. Critically, it surfaces the paid-per-call cost ($0.01 USDC via x402), which is essential behavioral context. It doesn't mention rate limits or error handling, but for a simple one-parameter read tool, this is strong transparency.
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: the first explains the core function and outputs, the second discloses pricing. No filler or redundant details, and it is front-loaded with the main purpose. Every sentence contributes value.
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 the single parameter, no output schema, and no annotations, the description covers the essential behavior: input (domain), processing (fetch/parse), output (score/findings/recommendations), and cost. It doesn't specify exact response structure, but that is acceptable without an output schema. It's nearly complete, only lacking explicit mention of potential network failures or data freshness.
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 provides 100% coverage for the single 'domain' parameter with a description. The tool description adds no new parameter-level information beyond confirming the domain is the subject, so it does not exceed the schema baseline. The parameter is simple and unambiguous.
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: it fetches, parses, and scores DMARC + SPF records for a domain, producing a 0-100 score with findings and fix recommendations. This distinguishes it from sibling tools like dns, rdap, or robots, which serve different functions.
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 purpose is self-explanatory and implicitly signals when to use this tool (when email authentication posture is needed). It does not explicitly name alternatives or exclusion criteria, but the context is clear enough to avoid confusion with sibling tools. A 5 would require explicit 'when not to use' or alternative tool references.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool addresses a distinct function: DNS resolution, email authentication, web extraction, legal entity lookup, QR generation, RDAP lookup, robots.txt parsing, sitemap parsing, text cleaning, and VAT calculation. There is no overlap or ambiguity between them.
All tool names are lowercase, concise, and use hyphens for compound words. Although some are nouns and some verbs, the style is uniform and each name clearly indicates its purpose, following a predictable convention.
With exactly 10 tools, the set is well-scoped for a general web utility server. Each tool covers a distinct need, and the count falls comfortably within the optimal 3-15 range.
The tools cover a comprehensive range of DNS, WHOIS, and domain-related functions, including DNS lookup, RDAP registration data, email auth, robots.txt, and sitemaps. The additional utilities (extract, text-clean, QR, LEI, VAT) round out the server without leaving obvious gaps in its stated purpose.
