runtime_hook_function · Js Reverse MCP: Risk & Policy

WHAT IT DOES

What runtime_hook_function does on Js Reverse

AI agents invoke runtime_hook_function 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 runtime_hook_function needs a policy

This tool injects runtime hooks into browser JavaScript functions, actively intercepting execution and capturing data. This is an Execute-category action because it dynamically modifies the runtime environment of a running browser process. Misuse could allow interception of sensitive credentials, encryption keys, or authentication tokens from arbitrary web pages, resulting in high severity.

From the tool's definition Hook指定函数，记录每次调用的参数和返回值（用于捕获加密过程的输入输出） — the tool hooks a specified function at runtime to intercept and record its arguments and return values

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

runtime_hook_function Rate-limited

runtime_hook_function 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": {
    "runtime_hook_function": {
      "limits": [
        {
          "counter": "runtime_hook_function_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 runtime_hook_function

What does the runtime_hook_function tool do? +

Hook指定函数，记录每次调用的参数和返回值（用于捕获加密过程的输入输出）. 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 runtime_hook_function? +

Register the Js Reverse MCP server in PolicyLayer and add a rule for runtime_hook_function: 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 runtime_hook_function? +

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

Can I rate-limit runtime_hook_function? +

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

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

runtime_hook_function 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.