tld-list-mcp

Search TLD variants

search_tld_variants

Read-onlyIdempotent

Compare up to 20 domain names across TLDs by checking availability and registration, renewal, transfer, and 3-year costs, with filters for price and registrar.

Instructions

Search one name or up to 20 names across TLDs. Batches TLD-List pricing, optionally filters by price/registrar and availability, and returns separate cheapest registration, renewal, transfer, and same-registrar 3-year costs. Popularity sorting is intentionally unavailable because API v1 does not document ranking data.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "search_tld_variants"
  }
}

Input Schema

Name	Required	Default
`name`	No
`tlds`	No
`limit`	No
`names`	No
`sortBy`	No	alphabetical
`registrars`	No
`availableOnly`	No
`maxRenewalPrice`	No
`maxTransferPrice`	No
`excludeRegistrars`	No
`maxRegistrationPrice`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.3Oct 1, 2026

TDQS

B3.4/5.0

Behavior4/5

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

Annotations already establish readOnly, idempotent, non-destructive, open-world behavior, so the description is free to add value — and it does: it discloses the return shape (separate cheapest registration, renewal, transfer, and same-registrar 3-year costs) and a hard API limitation (no popularity/ranking data in API v1). What it omits is any note on batching cost, latency, or what happens when a name has no available TLD.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences, front-loaded with the core action and followed by output and limitation facts; no filler. The 'intentionally unavailable' clause is longer than strictly needed but earns its place by preventing a wrong invocation.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, so describing the four return cost fields is necessary and done well. But for an 11-parameter, zero-required tool the description leaves key mechanics unaddressed: how name/names/tlds combine, default limit behavior, and the meaning of sortBy options.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0% across 11 parameters, so the description carries the burden; it does map several filters (price, registrar, availability) and the 1-or-20 name batch limit. However, it never explains the tlds parameter, the limit default/cap, the sortBy enum values, or how 'name' and 'names' interact, leaving roughly half the parameters undocumented anywhere.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Search one name or up to 20 names across TLDs') and adds concrete scope (batch pricing, optional availability/price/registrar filters). It is clear without opening the schema, but it never names a sibling such as compare_tlds or check_domain to disambiguate which search tool to pick.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains what the call returns and notes one excluded capability (popularity sorting), but gives no explicit guidance on when to choose this over compare_tlds, check_domain, or cheapest_registrar. Usage context is only implied by the feature list.

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

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