browser_tab_select · MCP Macaco Playwright MCP

WHAT IT DOES

What browser_tab_select does on MCP Macaco Playwright

AI agents invoke browser_tab_select to trigger actions in MCP Macaco Playwright. 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_tab_select needs a policy

Switching browser tabs is an active browser control operation that changes the browser's state and triggers automatic page snapshot capture. This is an Execute-category action as it performs a browser action with side effects (tab focus change, snapshot capture), not merely reading data.

From the tool's definition Switch to a specific browser tab by its index position... automatically captures a page snapshot

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

browser_tab_select Rate-limited

browser_tab_select 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_tab_select": {
      "limits": [
        {
          "counter": "browser_tab_select_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 MCP Macaco Playwright, so you can run agents against it safely.

FAQ

Questions about browser_tab_select

What does the browser_tab_select tool do? +

Switch to a specific browser tab by its index position. After selecting the tab, automatically captures a page snapshot to provide the current state of the selected tab. It is categorised as a Execute tool in the MCP Macaco Playwright 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_tab_select? +

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

What risk level is browser_tab_select? +

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

Can I rate-limit browser_tab_select? +

Yes. Add a rate_limit block to the browser_tab_select 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_tab_select completely? +

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

browser_tab_select is provided by the MCP Macaco Playwright MCP server (macacoai/mcp-playwright). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.