crawl_site · Screaming Frog MCP: Risk & Policy

WHAT IT DOES

What crawl_site does on Screaming Frog

AI agents invoke crawl_site to trigger actions in Screaming Frog. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why crawl_site needs a policy

The tool name and server context strongly imply this tool initiates a web crawl, which is an external operation with real-world effects (network requests to target sites). The description is empty, which lowers confidence, but the server description explicitly mentions 'crawling sites' as a primary function. Crawling a site can consume significant resources, trigger rate limits, or violate terms of service.

From the tool's definition Tool name 'crawl_site' on a server described as providing 'tools for crawling sites' — the tool triggers an external crawl operation against a target website.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

crawl_site Rate-limited

crawl_site stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "crawl_site": {
      "limits": [
        {
          "counter": "crawl_site_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Screaming Frog, so you can run agents against it safely.

FAQ

Questions about crawl_site

What does the crawl_site tool do? +

crawl_site. It is categorised as a Execute tool in the Screaming Frog MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on crawl_site? +

Register the Screaming Frog MCP server in PolicyLayer and add a rule for crawl_site: 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 Screaming Frog. Nothing to install.

What risk level is crawl_site? +

crawl_site is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit crawl_site? +

Yes. Add a rate_limit block to the crawl_site 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.

How do I block crawl_site completely? +

Set action: deny in the PolicyLayer policy for crawl_site. 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.

What MCP server provides crawl_site? +

crawl_site is provided by the Screaming Frog MCP server (marykovziridze/screaming-frog-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.