browser_tab_list

List browser tabs

SERVERCowork Bench SOURCE0717376/cowork_bench

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/cowork-bench/browser-tab-list.md

WHAT IT DOES

What browser_tab_list does on Cowork Bench

AI agents call browser_tab_list to retrieve information from Cowork Bench without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why browser_tab_list is rated Low

This is a read-only operation that retrieves state information (list of open tabs) with no side effects, no code execution, and no modifications to data or system state. The minimal information disclosed (tab list) poses low risk even in adversarial use.

From the tool's definition Tool name 'browser_tab_list' and description 'List browser tabs' indicate a query operation that retrieves information about open browser tabs without modifying or executing anything.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs browser_tab_list safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Cowork Bench, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For browser_tab_list, this is the rule to start with:

browser_tab_list Allowed

browser_tab_list is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

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

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Cowork Bench, apply this rule, and every browser_tab_list call is checked against it from then on.

FAQ

Questions about browser_tab_list

What does the browser_tab_list tool do? +

List browser tabs. It is categorised as a Read tool in the Cowork Bench MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on browser_tab_list? +

Register the Cowork Bench MCP server in PolicyLayer and add a rule for browser_tab_list: 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 Cowork Bench. Nothing to install.

What risk level is browser_tab_list? +

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

Can I rate-limit browser_tab_list? +

Yes. Add a rate_limit block to the browser_tab_list 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_list completely? +

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

browser_tab_list is provided by the Cowork Bench MCP server (0717376/cowork_bench). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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