playwright_test_ui · UI/UX MCP Server MCP: Risk & Policy

WHAT IT DOES

What playwright_test_ui does on UI/UX MCP Server

AI agents invoke playwright_test_ui to trigger actions in UI/UX MCP Server. 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 playwright_test_ui needs a policy

This tool runs Playwright tests, which involves executing browser automation scripts. The effects depend on the test scripts being run, which could include navigating pages, clicking elements, filling forms, and triggering external operations.

From the tool's definition 'Run UI tests with Playwright' — executes automated browser-based test scripts via Playwright

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

playwright_test_ui Rate-limited

playwright_test_ui 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": {
    "playwright_test_ui": {
      "limits": [
        {
          "counter": "playwright_test_ui_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 UI/UX MCP Server, so you can run agents against it safely.

FAQ

Questions about playwright_test_ui

What does the playwright_test_ui tool do? +

Run UI tests with Playwright. It is categorised as a Execute tool in the UI/UX MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on playwright_test_ui? +

Register the UI/UX MCP Server MCP server in PolicyLayer and add a rule for playwright_test_ui: 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 UI/UX MCP Server. Nothing to install.

What risk level is playwright_test_ui? +

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

Can I rate-limit playwright_test_ui? +

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

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

playwright_test_ui is provided by the UI/UX MCP Server MCP server (willem4130/ui-ux-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.