VAT calculator for EU-27 + UK: net→gross or gross→net at standard or reduced rate. Includes rates table snapshot date. Paid per call: $0.002 in USDC via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| rate | No | default standard | |
| amount | Yes | ||
| country | Yes | ISO 3166-1 alpha-2, e.g. DE, FR, GB | |
| direction | No | default net_to_gross |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It discloses the per-call cost ($0.002 USDC via x402) and the rates table snapshot date, which are important behavioral traits. However, it does not mention error handling or the exact return format, which would be useful since there is no output 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?
The description is two sentences, front-loaded with the core functionality, followed by cost and data snapshot context. Every sentence earns its place with no fluff or 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?
The tool is simple, but since there is no output schema, the description does not state what the response looks like (e.g., whether it returns just the converted amount or both net and gross values). It also does not mention the actual snapshot date, which is referenced but not provided. These gaps make it slightly incomplete for fully autonomous invocation.
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 75%, and the description adds meaning by explaining the direction (net→gross or gross→net) and rate categories (standard or reduced), which clarifies the enum parameters. It also implies what 'amount' represents. This goes beyond just repeating schema field descriptions.
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 it is a VAT calculator for EU-27 + UK, with specific operations (net→gross or gross→net) and rate types (standard or reduced). It distinguishes itself from sibling tools, which are all in different domains (DNS, email, QR, etc.).
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 when to use the tool (when VAT conversion is needed for EU/UK), but it does not explicitly state alternatives or exclusion conditions. The sibling tools are unrelated, so no alternative is mentioned, but the usage context is not explicitly spelled out.
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.
