Check name availability on 70+ platforms: domains, social networks, marketplaces.
Scored across 3 tools
check_domains and check_name both check domain availability, creating some overlap, but the descriptions clearly differentiate them: check_domains bulk-compares up to 10 names across extensions, while check_name does a broad single-name check across 70+ platforms. The guidance to use check_domains first then check_name on a shortlist further reduces confusion, and suggest_names has a distinct generation purpose.
All three tools follow a consistent verb_noun snake_case pattern (check_domains, check_name, suggest_names). The convention is predictable and readable throughout.
Three tools is slightly thin but well-matched to the narrow scope of domain/name availability checking. Each tool earns its place with a distinct role in the workflow (bulk check, broad check, variant generation).
The set covers a sensible workflow: bulk domain comparison, cross-platform handle checks, and variant suggestions with registration links and pricing. Minor gaps exist, such as no explicit tool for detailed single-domain registration or price comparison, but core needs are met.
Checks domain name availability for up to 10 names on chosen extensions (DNS + RDAP registry lookup). Default extensions: .com, .net, .org, .io, .app, .dev, .co, .fr. Supported: .com, .fr, .net, .org, .info, .biz, .co, .de, .uk, .it, .es, .be, .ch, .nl, .eu, .ca, .us, .io, .ai, .me, .gg, .tv, .app, .dev, .tech, .studio, .design, .art, .shop, .store, .online, .xyz. Ideal to compare several name ideas quickly. Available domains come with a registration link and indicative price.
| Name | Required | Description | Default |
|---|---|---|---|
| tlds | No | Extensions to check, without dot (default: main ones) | |
| names | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnly, idempotent, openWorld), so the description is not obligated to restate them. It adds real behavioral context beyond that: the 10-name cap, the two lookup stages (DNS + RDAP), the default extension set, and the fact that available domains return a registration link and indicative price. It does not mention rate limits or failure behavior for malformed labels.
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?
Purpose, mechanism, and defaults are front-loaded, which is good. However, enumerating all 32 supported extensions duplicates the input schema's enum verbatim and consumes roughly half the description without adding information the agent cannot already see.
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?
There is no output schema, so the description carries the return-value burden and does so partially, explaining that available names return a registration link and price. It omits how unavailable names are reported and any batch/pagination behavior, but for a two-parameter lookup tool this is close to 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?
With 50% schema coverage, the description compensates well: it names the eight default TLDs, where the schema only says 'default: main ones', and restates the 10-name ceiling and no-dot label convention. The full 32-entry supported list is useful because the enum is not self-explanatory about defaults, though it does repeat the schema.
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 gives a specific verb and resource ('Checks domain name availability'), states the mechanism (DNS + RDAP registry lookup) and the batch limit (up to 10 names). It is clearly distinct from suggest_names, though it does not explicitly contrast itself with check_name, which is the nearest sibling.
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?
'Ideal to compare several name ideas quickly' is a soft benefit statement rather than a usage rule; it implies when the tool shines but gives no exclusions and never routes the agent to check_name or suggest_names. Adequate but leaves the sibling choice to inference.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Checks whether a name/handle is available on 70+ platforms at once: domain names (.com, .fr, .io, .app…), social networks (Instagram, TikTok, X, YouTube…), creative and dev platforms (GitHub, Behance…), e-commerce, freelance, gaming and company registries. Takes 5-15 s on first call (results cached 10 min). Statuses: available, likely_available, taken, manual (cannot be checked automatically), unknown (check failed). Never present manual/unknown results as available. Available domains come with a registration link. Each call is a full live search: to compare many name ideas, first use check_domains (up to 10 names per call), then check_name only on the shortlist.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | Name or handle to check (2-50 chars: letters, digits, . - _) | |
| categories | No | Optional: only return these categories (all by default) |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Goes well beyond the readOnly/openWorld/idempotent annotations by disclosing latency (5-15 s first call), caching window (10 min), the full status vocabulary, a critical caveat ('Never present manual/unknown results as available'), and that available domains include a registration link. This is unusually rich operational context.
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?
Dense and front-loaded: capability first, then timing/caching, then status semantics, then the sibling-routing rule. Every sentence carries operational information an agent needs; none is 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?
With no output schema, the description still conveys the response shape (status values, registration links) and the safety-critical interpretation rule. Nothing material for correct invocation is missing.
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%, so the baseline is 3, but the description earns extra credit by explaining what the scoping actually covers (domain TLDs, social networks, creative/dev, e-commerce, freelance, gaming, registries), which maps partially onto the categories enum and lets an agent reason about narrowing results.
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?
States a specific verb and resource ('Checks whether a name/handle is available on 70+ platforms at once') and enumerates the concrete platform classes covered. An agent can distinguish this from check_domains and suggest_names purely from the description.
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?
Explicit routing guidance: 'to compare many name ideas, first use check_domains (up to 10 names per call), then check_name only on the shortlist.' It names the alternative and the condition that selects it, which is exactly what an agent needs for tool selection.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Generates common variants of a name (get-, try-, -hq, -app, -studio…) and checks which ones are available as a domain (.com by default). Use when the exact name is taken.
| Name | Required | Description | Default |
|---|---|---|---|
| tld | No | Extension to check, default com | |
| name | Yes | Base name, letters/digits/hyphens |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover readOnly, openWorld, and idempotent, so the safety profile is known. The description adds useful context (which patterns, default TLD), but doesn't mention rate limits, number of suggestions, or the network-dependent nature beyond what openWorldHint implies.
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?
Two tight sentences with the generation logic front-loaded and the usage trigger second. No 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?
For a read-only, two-parameter, idempotent tool with no output schema and full schema coverage, the description is nearly complete. It could mention how many results or the output shape, but the essentials for correct invocation are present.
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 the tld enum and name pattern fully documented in the schema. The description echoes the '.com by default' default but adds no syntax or format beyond the schema, so baseline 3 applies.
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?
Specific verb (generates, checks) and resource (name variants, domain availability), and it even enumerates the variant patterns. An agent can distinguish this from check_domains and check_name without opening a schema.
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?
Explicitly states the trigger condition 'Use when the exact name is taken,' which gives clear when-to-use guidance. It does not explicitly name sibling alternatives or when-not-to-use, keeping it short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
check_domainscheck_namesuggest_namesCheck brand name availability on Instagram, TikTok, X, YouTube, GitHub and more in one call
Check a name on 29 platforms and the domains; build and follow apps you own on SPOE.
Check if a brand name is free across domains, GitHub, npm and PyPI, and suggest available names.
Checks if a project, brand or app name already exists: trademarks, domains, web and GitHub.
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