check_domainsUse this when the user wants to know whether one or more domains are available to register. Returns confidence, source, cache age, and ambiguous results when the lookup cannot be determined safely.
| Name | Required | Description | Default |
|---|---|---|---|
| domains | Yes |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/openWorld/idempotent, so no credit for that. Description adds value by disclosing return fields (confidence, source, cache age) and ambiguous result handling, which is behavior not visible elsewhere.
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 sentences, front-loaded with usage trigger, then return details. No filler 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?
For a simple read-only lookup with one parameter, the description covers purpose, return values, and edge-case behavior (ambiguous results). It lacks deeper details on interpreting confidence/cache age and domain format, but annotations plus schema make the tool usable.
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 only parameter is 'domains' (array of strings), and description says 'one or more domains,' reinforcing plurality. However, schema coverage is 0% and description does not specify expected domain format (e.g., no protocol, TLD required), leaving room for ambiguity.
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 uses a specific verb and resource: 'whether one or more domains are available to register.' This clearly distinguishes from siblings by focusing on registration availability rather than usage or general info.
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?
Starts with 'Use this when...' giving explicit trigger context. It doesn't provide exclusions or compare with sibling tools, but the context is clear enough to avoid overlap with check_usage or get_domain_info.
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 targets a distinct concern: check_domains for availability, get_domain_info for WHOIS/registration details, and check_usage for account quota. There is no overlap between availability and ownership information, so confusion is unlikely.
All tool names follow a consistent verb_noun pattern using lowercase snake_case. check_domains, check_usage, and get_domain_info are uniform in structure, with verbs and nouns clearly indicating the action and target.
With exactly 3 tools, the server is tightly scoped to its purpose of checking domain availability and providing registration info. This is within the well-scoped range and each tool earns its place without redundancy.
The set covers the core domain lookup workflows: availability checking, detailed WHOIS, and user quota. A minor gap is the absence of a domain suggestion or bulk search feature, but for the stated purpose the coverage is largely complete.