chrome_activate_tab · Nextjs Agent MCP: Risk & Policy

WHAT IT DOES

What chrome_activate_tab does on Nextjs Agent

AI agents invoke chrome_activate_tab to trigger actions in Nextjs Agent. 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 chrome_activate_tab needs a policy

This tool performs a browser action (activating/focusing a tab), which is an external operation. It doesn't read data, write/modify data persistently, or delete anything, but it does drive a real browser interaction. Severity is medium since it could be used to manipulate browser state and expose content, though the direct blast radius is limited.

From the tool's definition chrome_activate_tab — brings a browser tab to the foreground; triggers an external browser operation (tab focus/activation)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

chrome_activate_tab Rate-limited

chrome_activate_tab 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": {
    "chrome_activate_tab": {
      "limits": [
        {
          "counter": "chrome_activate_tab_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 Nextjs Agent, so you can run agents against it safely.

FAQ

Questions about chrome_activate_tab

What does the chrome_activate_tab tool do? +

Bring a browser tab to the foreground by its. It is categorised as a Execute tool in the Nextjs Agent MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on chrome_activate_tab? +

Register the Nextjs Agent MCP server in PolicyLayer and add a rule for chrome_activate_tab: 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 Nextjs Agent. Nothing to install.

What risk level is chrome_activate_tab? +

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

Can I rate-limit chrome_activate_tab? +

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

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

chrome_activate_tab is provided by the Nextjs Agent MCP server (zohaib3249/nextjs-agent-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.