scroll_page · JS Reverse MCP: Risk & Policy

WHAT IT DOES

What scroll_page does on JS Reverse MCP

AI agents invoke scroll_page to trigger actions in JS Reverse MCP. 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 scroll_page needs a policy

Scrolling is a browser action that executes within a controlled browser environment. While seemingly benign, in the context of a reverse engineering/debugging server with hook injection capabilities, scrolling can trigger JavaScript event listeners, cause lazy-loaded content to execute, or advance automated attack workflows. It is an Execute-category action (browser interaction) rather than a simple Read or Write.

From the tool's definition Scroll the page to absolute x/y coordinates — triggers a browser action (scrolling) that interacts with a live browser session

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

scroll_page Rate-limited

scroll_page 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": {
    "scroll_page": {
      "limits": [
        {
          "counter": "scroll_page_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 JS Reverse MCP, so you can run agents against it safely.

FAQ

Questions about scroll_page

What does the scroll_page tool do? +

Scroll the page to absolute x/y coordinates. It is categorised as a Execute tool in the JS Reverse MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on scroll_page? +

Register the JS Reverse MCP server in PolicyLayer and add a rule for scroll_page: 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 JS Reverse MCP. Nothing to install.

What risk level is scroll_page? +

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

Can I rate-limit scroll_page? +

Yes. Add a rate_limit block to the scroll_page 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 scroll_page completely? +

Set action: deny in the PolicyLayer policy for scroll_page. 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 scroll_page? +

scroll_page is provided by the JS Reverse MCP server (noone-hub/jsreverser-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.