Quick check if a domain can receive email. Returns MX records and catch-all status.
AI agents call check_domain to retrieve information from Prospector MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves email infrastructure information (MX records, catch-all detection) via DNS queries. DNS lookups are read-only operations with no side effects, data modification, or external execution. While email discovery could enable spam or targeted attacks, the tool itself is purely informational and falls squarely in the Read category.
From the tool's definition Tool performs DNS lookup to check MX records and catch-all status—a read-only query operation with no modification, deletion, or execution of code. Description states it 'returns' information about whether a domain can receive email, indicating data retrieval.
Attacks that exploit this kind of access
Quick check if a domain can receive email. Returns MX records and catch-all status. It is categorised as a Read tool in the Prospector MCP MCP Server, which means it retrieves data without modifying state.
Register the Prospector MCP server in PolicyLayer and add a rule for check_domain: 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 Prospector MCP. Nothing to install.
check_domain 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 check_domain 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 check_domain. 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.
check_domain is provided by the Prospector MCP server (josiebot26/prospector-mcp-email-finder). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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