set_url_tab

Set url tab (tab id, url)

SERVERBrowser SOURCEmcp-server-browser

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/browser/set-url-tab.md

WHAT IT DOES

What set_url_tab does on Browser

AI agents invoke set_url_tab to trigger actions in Browser. 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.

RISK

Why set_url_tab is rated High

Navigating a tab to a URL is an external operation that can load arbitrary web pages, trigger scripts, initiate downloads, or interact with web services. It goes beyond a simple read or write since it drives browser behavior and can have wide-ranging side effects depending on the URL provided.

From the tool's definition "Set url tab (tab id, url)" — navigates a browser tab to an arbitrary URL, triggering external network requests and page execution

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs set_url_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 set_url_tab, this is the rule to start with:

set_url_tab Rate-limited

set_url_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": {
    "set_url_tab": {
      "limits": [
        {
          "counter": "set_url_tab_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about set_url_tab

What does the set_url_tab tool do? +

Set url tab (tab id, url). It is categorised as a Execute tool in the Browser MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on set_url_tab? +

Register the Browser MCP server in PolicyLayer and add a rule for set_url_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 set_url_tab? +

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

Can I rate-limit set_url_tab? +

Yes. Add a rate_limit block to the set_url_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 set_url_tab completely? +

Set action: deny in the PolicyLayer policy for set_url_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 set_url_tab? +

set_url_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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