puppeteer_wait_for_function

THE RISK

High Risk

Why puppeteer_wait_for_function needs a policy

This tool allows execution of arbitrary JavaScript code in a browser context. While it doesn't directly delete data or move money, it can trigger any side effects that JavaScript can perform in a browser (DOM manipulation, fetch requests, local storage access, form submissions, navigation).

From the tool's definition Tool executes arbitrary JavaScript functions via 'puppeteer' browser automation in a wait loop until a function returns true.

Documented attack patterns abuse exactly the kind of access puppeteer_wait_for_function gives an agent:

POLICY

How to control puppeteer_wait_for_function

PolicyLayer is an MCP gateway — it sits between your AI agents and Claude TypeScript MCP Servers, and nothing reaches the server without passing your rules. This is the rule we recommend for puppeteer_wait_for_function:

policy.json

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

puppeteer_wait_for_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.

Create a free account and register Claude TypeScript MCP Servers — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RATE-LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Claude TypeScript MCP Servers tools

Destructive delete_file Delete a file. This operation cannot be undone. Only works within allowed directories. Destructive delete_release Delete a release Execute puppeteer_clear_input Clear an input field Execute batch_operations Execute multiple file operations efficiently. Supports transactional mode (rollback on err Execute puppeteer_emulate_device Emulate a specific device Execute puppeteer_evaluate Execute JavaScript in the browser console Execute puppeteer_evaluate_in_frame Execute JavaScript in a specific frame Execute puppeteer_navigate Navigate to a URL

All 84 Claude TypeScript MCP Servers tools →

Execute tools on other servers

Android Forensics ADB MCP Server adb_shell_command EMBA-MCP run_emba_scan Frida Game Hacking MCP remove_breakpoint Procmon request_elevation

Go deeper

High-risk tools in Claude TypeScript MCP Servers → Every high-risk tool this server exposes, in one view.
All high-risk MCP tools → Every high-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Agent sandbox → Bounding what an agent can execute and where the boundary should sit.
Least privilege for MCP → Granting agents the minimum tool surface the task needs.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about puppeteer_wait_for_function

What does the puppeteer_wait_for_function tool do? +

Wait for a JavaScript function to return true. It is categorised as a Execute tool in the Claude TypeScript MCP Servers MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on puppeteer_wait_for_function? +

Register the Claude TypeScript MCP Servers MCP server in PolicyLayer and add a rule for puppeteer_wait_for_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 Claude TypeScript MCP Servers. Nothing to install.

What risk level is puppeteer_wait_for_function? +

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

Can I rate-limit puppeteer_wait_for_function? +

Yes. Add a rate_limit block to the puppeteer_wait_for_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 puppeteer_wait_for_function completely? +

Set action: deny in the PolicyLayer policy for puppeteer_wait_for_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 puppeteer_wait_for_function? +

puppeteer_wait_for_function is provided by the Claude TypeScript MCP Servers MCP server (ukkz/claude-ts-mcps). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Claude TypeScript MCP Servers tool call.

Start from Claude TypeScript MCP Servers, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →