AI agents call check-status to retrieve information from MCP Node Fetch without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool only checks whether a URL is accessible by making a HEAD request. HEAD requests are read operations that do not retrieve body content and have no side effects. The blast radius is minimal—at worst, it could be used for reconnaissance or to probe the availability of endpoints, but it cannot modify, execute, or delete anything. Therefore, it is classified as Read with low severity.
From the tool's definition The tool performs a HEAD request to check URL accessibility, which is a read-only operation that retrieves only HTTP headers without fetching the full content or modifying any data.
Documented attack patterns abuse exactly the kind of access check-status gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Node Fetch, and nothing reaches the server without passing your rules. This is the rule we recommend for check-status:
{
"version": "1",
"default": "deny",
"tools": {
"check-status": {}
}
}check-status is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check if a URL is accessible (HEAD request). It is categorised as a Read tool in the MCP Node Fetch MCP Server, which means it retrieves data without modifying state.
Register the MCP Node Fetch MCP server in PolicyLayer and add a rule for check-status: 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 MCP Node Fetch. Nothing to install.
check-status 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-status 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-status. 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-status is provided by the MCP Node Fetch MCP server (mcollina/mcp-node-fetch). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP Node Fetch, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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3 MCP Node Fetch tools catalogued and risk-classified — across an index of 43,000+ MCP servers.