list_browser_tabs

List all active browser tabs running this application. Returns tab IDs, URLs, titles, and active status. Use this to discover available tabs before calling tools with specific tabId parameters.

ServerReact Tools
CategoryRead

How to control list_browser_tabs ↓

WHAT IT DOES

What list_browser_tabs does on React Tools

AI agents call list_browser_tabs to retrieve information from React Tools without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

THE RISK

Low Risk

Why list_browser_tabs needs a policy

This is a pure information retrieval operation. It queries the state of open browser tabs and returns read-only metadata. There is no data creation, modification, deletion, code execution, or financial impact. The tool serves only to discover available tabs before other operations, making it a straightforward Read category tool with low risk.

From the tool's definition Tool name and description: 'List all active browser tabs' — retrieves tab metadata (IDs, URLs, titles, active status) with no modification or side effects.

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

POLICY

How to control list_browser_tabs

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

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_browser_tabs": {}
  }
}

list_browser_tabs is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.

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

CAP THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More React Tools tools

Execute app_navigate List available routes or navigate to a path in the app. Call without Execute admin_action Perform admin action Execute validate_form Run validation on the current form state and return all errors Write fill_field Fill a specific form field with a value. Write submit_form Validate and submit the registration form. Returns validation errors if form is invalid, o Read client_status Check if there is a client connected via WebSocket Read get_click_events Get user click events Read get_field_info Get detailed information about a specific form field

All 20 React Tools tools →

Read tools on other servers

M-Team MCP Server get_torrent_detail YouTube MCP Server search_channel Android Forensics ADB MCP Server parse_browser_history 0xarchive web3_challenge

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Data exfiltration → How read access becomes an exfiltration channel when chained with untrusted content.
MCP token cost → What connecting this server costs in context-window tokens on every request.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about list_browser_tabs

What does the list_browser_tabs tool do? +

List all active browser tabs running this application. Returns tab IDs, URLs, titles, and active status. Use this to discover available tabs before calling tools with specific tabId parameters. It is categorised as a Read tool in the React Tools MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_browser_tabs? +

Register the React Tools MCP server in PolicyLayer and add a rule for list_browser_tabs: 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 React Tools. Nothing to install.

What risk level is list_browser_tabs? +

list_browser_tabs is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit list_browser_tabs? +

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

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

list_browser_tabs is provided by the React Tools MCP server (mcp-fe/mcp-fe). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every React Tools tool call.

Start from React Tools, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →

Free to start. No card required.

20 React Tools tools catalogued and risk-classified — across an index of 43,000+ MCP servers.