AI agents call check_blacklist to retrieve information from Intodns without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a read-only query tool that retrieves blacklist status information without creating, modifying, or deleting any data. While false positives in blacklist lookups could have business impact, the tool itself performs no side effects and presents minimal direct risk from misuse.
From the tool's definition Tool description explicitly states "Read-only query" and lists it among "free tools for DNS, DMARC, SPF, DKIM...blacklist and email security checks." The function checks IP/domain reputation against public blacklist feeds with no mutation capability.
Attacks that exploit this kind of access
Read-only query against ~80 public DNSBL/RBL/URIBL feeds. Provide either. It is categorised as a Read tool in the Intodns MCP Server, which means it retrieves data without modifying state.
Register the Intodns MCP server in PolicyLayer and add a rule for check_blacklist: 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 Intodns. Nothing to install.
check_blacklist 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_blacklist 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_blacklist. 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_blacklist is provided by the Intodns MCP server (rosconl/intodns-mcp-server). 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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