page_navigate · Js Reverse MCP: Risk & Policy

WHAT IT DOES

What page_navigate does on Js Reverse

AI agents invoke page_navigate to trigger actions in Js Reverse. 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 page_navigate needs a policy

Navigation to arbitrary URLs constitutes code/operation execution in a browser context. The tool's effect (which site is visited, what scripts run) entirely depends on the URL argument provided by an AI agent. While not irreversible (Destructive) or financial in nature, it crosses into Execute territory because it triggers external operations and remote code execution via the browser.

From the tool's definition Tool navigates to a specified URL and waits for page load completion. This triggers external operations (HTTP requests, page rendering, script execution) whose effects depend on the URL argument.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

page_navigate Rate-limited

page_navigate 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": {
    "page_navigate": {
      "limits": [
        {
          "counter": "page_navigate_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, so you can run agents against it safely.

FAQ

Questions about page_navigate

What does the page_navigate tool do? +

导航到指定URL，等待页面加载完成. It is categorised as a Execute tool in the Js Reverse MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on page_navigate? +

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

What risk level is page_navigate? +

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

Can I rate-limit page_navigate? +

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

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

page_navigate is provided by the Js Reverse MCP server (jenn619/js-reverse-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.