Free public API. Check availability of a name across one or more TLDs. Pass a name (no TLD) and an optional tlds array.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Bare name without TLD, e.g. `mybrand`. | |
| tlds | No | Optional list of TLDs to check, e.g. ['com', 'io', 'dev']. Default: a standard SaaS set. |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already convey read-only, idempotent, and non-destructive behavior. The description adds valuable context by noting it is a 'Free public API' (implying no authentication) and clarifies that it checks across 'one or more TLDs.' This goes beyond the annotations without contradicting them.
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 extremely concise, consisting of three short sentences. It front-loads the 'Free public API' context, states the core function, and gives parameter guidance without any wasted words. 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 tool's simplicity (two params, no nested structure) and strong annotations, the description adequately covers what the tool does and how to call it. The only minor gap is the lack of mention of output format, but this is mitigated by the tool's name and clear purpose.
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 100% with meaningful descriptions for both parameters. The description's 'Pass a `name` (no TLD) and an optional `tlds` array' largely repeats the schema, adding no new semantic information. This aligns with the baseline of 3 for full schema coverage.
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 function: 'Check availability of a name across one or more TLDs.' This is a specific verb-resource pairing that distinguishes it from sibling DNS-related tools like whois_lookup or dns_record_lookup. The scope is explicit and unambiguous.
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 usage context by stating it is a 'Free public API' and instructs how to pass the `name` and optional `tlds` array. It does not explicitly mention exclusions or alternatives, but the tool's purpose is distinct enough among siblings that no additional guidance is necessary.
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.
Multiple tools operate in the same DNS/domain space, e.g., generic DNS record lookup overlaps with specific CNAME, TXT, SPF, DKIM, and DMARC lookups. Website status checker also overlaps with SSL check and redirect checker, though descriptions clarify their distinct purposes.
All tool names follow a consistent snake_case pattern with a 'tools_' prefix and an action word at the end (lookup, checker, check, finder). This makes the naming highly predictable and uniform.
16 tools is slightly above the ideal 3-15 range, but the domain intelligence scope is broad enough that each tool addresses a specific need without feeling bloated. The count is reasonable for a comprehensive domain/DNS toolkit.
The tool set covers a wide range of domain-related functionality: DNS records, email authentication (SPF, DKIM, DMARC), SSL/TLS, HTTP headers, redirects, WHOIS, availability, subdomain enumeration, and website status. No obvious critical gaps exist for its apparent purpose.
