unpin_active_tab

Unpin active tab (tab id)

SERVERBrowser SOURCEmcp-server-browser

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/browser/unpin-active-tab.md

WHAT IT DOES

What unpin_active_tab does on Browser

AI agents use unpin_active_tab to create or update resources in Browser, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Browser environment.

RISK

Why unpin_active_tab is rated Medium

Unpinning a tab modifies the state of the browser tab (removes its pinned status) but is reversible — the tab can be pinned again. This is a write/modify operation with minimal blast radius, as it only affects tab UI state and does not delete data or execute code.

From the tool's definition Unpin active tab (tab id)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs unpin_active_tab safely

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

unpin_active_tab Rate-limited

unpin_active_tab stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "unpin_active_tab": {
      "limits": [
        {
          "counter": "unpin_active_tab_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about unpin_active_tab

What does the unpin_active_tab tool do? +

Unpin active tab (tab id). It is categorised as a Write tool in the Browser MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on unpin_active_tab? +

Register the Browser MCP server in PolicyLayer and add a rule for unpin_active_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 Browser. Nothing to install.

What risk level is unpin_active_tab? +

unpin_active_tab is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit unpin_active_tab? +

Yes. Add a rate_limit block to the unpin_active_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 unpin_active_tab completely? +

Set action: deny in the PolicyLayer policy for unpin_active_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 unpin_active_tab? +

unpin_active_tab is provided by the Browser MCP server (mcp-server-browser). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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