browser_select_option · Playwright MCP: Risk & Policy

WHAT IT DOES

What browser_select_option does on Playwright MCP

AI agents invoke browser_select_option to trigger actions in Playwright 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 browser_select_option needs a policy

Selecting a dropdown option is a browser action that changes the state of a form element on a web page, potentially triggering downstream events (onChange handlers, form submissions, navigation). It is an interactive browser operation classified as Execute, with medium severity since it can affect form state and trigger application logic depending on what option is selected.

From the tool's definition 'Select an option in a dropdown' — triggers a browser UI interaction that modifies the state of a web page element

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_select_option Rate-limited

browser_select_option 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": {
    "browser_select_option": {
      "limits": [
        {
          "counter": "browser_select_option_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Playwright MCP, so you can run agents against it safely.

FAQ

Questions about browser_select_option

What does the browser_select_option tool do? +

Select an option in a dropdown. It is categorised as a Execute tool in the Playwright 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 browser_select_option? +

Register the Playwright MCP server in PolicyLayer and add a rule for browser_select_option: 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 Playwright MCP. Nothing to install.

What risk level is browser_select_option? +

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

Can I rate-limit browser_select_option? +

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

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

browser_select_option is provided by the Playwright MCP server (nzjami/mcpplaywright). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.