AI agents call search__one_greynoise to retrieve information from SeldomMaster without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool retrieves threat intelligence data about IP addresses/ASNs from GreyNoise's database without modifying, executing code, or causing destructive action. This is a read-only reconnaissance query. Severity is low because the blast radius of misuse is limited to information disclosure about publicly known threat data, not direct system compromise or data destruction.
From the tool's definition Tool name 'search_greynoise' and description prefix 'search' indicate a query operation against GreyNoise threat intelligence API. GreyNoise is a passive IP intelligence service for looking up known malicious IPs and ASNs.
Documented attack patterns abuse exactly the kind of access search__one_greynoise gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SeldomMaster, and nothing reaches the server without passing your rules. This is the rule we recommend for search__one_greynoise:
{
"version": "1",
"default": "deny",
"tools": {
"search__one_greynoise": {}
}
}search__one_greynoise is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Name: search_greynoise. It is categorised as a Read tool in the SeldomMaster MCP Server, which means it retrieves data without modifying state.
Register the SeldomMaster MCP server in PolicyLayer and add a rule for search__one_greynoise: 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 SeldomMaster. Nothing to install.
search__one_greynoise 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 search__one_greynoise 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 search__one_greynoise. 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.
search__one_greynoise is provided by the SeldomMaster MCP server (paralax/seldommonster). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from SeldomMaster, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
52 SeldomMaster tools catalogued and risk-classified — across an index of 43,000+ MCP servers.