Check a keyword prefix's registration status across all TLDs. Returns total registration count (gTLDs + ccTLDs) and status of core TLDs (com, net, org, io, ai, de). This is a saturation and popularity metric — the total count indicates how widely a keyword has been claimed across the TLD namespac...
Part of the DomainKits server.
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AI agents call tld_check to retrieve information from DomainKits without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though tld_check only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"tld_check": {}
}
}See the full DomainKits policy for all 38 tools.
These attack patterns abuse exactly the kind of access tld_check gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Check a keyword prefix's registration status across all TLDs. Returns total registration count (gTLDs + ccTLDs) and status of core TLDs (com, net, org, io, ai, de). This is a saturation and popularity metric — the total count indicates how widely a keyword has been claimed across the TLD namespace. Interpreting results: - count >200: Keyword is widely recognized — either high market demand or strong brand protection (or both). Cross-reference with keyword_data and active to determine which. - count 50-200: Worth attention — check if there are still opportunities available. - count <50: Not a particularly popular keyword in the domain market. - gtlds_count vs cctlds_count ratio: High ccTLD registration suggests international interest in the keyword. The tlds field shows status for core TLDs (com, net, org, io, ai, de) with values: 'registered', 'for_sale', 'expiring', or 'might_available'. Note that 'might_available' means the prefix is not found in our database for that TLD — confirm with the 'available' tool before assuming registrability. Best practices: - The prefix parameter must NOT contain the TLD extension — use 'openai' not 'openai.com'. - If .com shows 'might_available' for an established keyword, this is unusual and worth verifying. - If .com shows 'for_sale' or 'expiring', this is a potential acquisition opportunity worth flagging.. It is categorised as a Read tool in the DomainKits MCP Server, which means it retrieves data without modifying state.
Register the DomainKits MCP server in PolicyLayer and add a rule for tld_check: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches DomainKits. Nothing to install.
tld_check is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the tld_check rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for tld_check. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
tld_check is provided by the DomainKits MCP server (https://api.domainkits.com/v1/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 38 DomainKits tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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