AI agents invoke browser_tab_new to trigger actions in Playwright MCP. 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.
This tool executes a browser command (tab creation) whose downstream effects depend on what content the agent loads and interacts with in that tab. While opening a tab alone is not destructive or financial, it enables further browser automation (navigation, file uploads, interactions) and thus qualifies as Execute rather than Write.
From the tool's definition Tool description states 'Open a new tab', which triggers a browser action. Sibling tools like 'browser_click', 'browser_navigate', 'browser_drag', and 'browser_file_upload' confirm this server enables external operations with side effects.
Documented attack patterns abuse exactly the kind of access browser_tab_new gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_tab_new:
{
"version": "1",
"default": "deny",
"tools": {
"browser_tab_new": {
"limits": [
{
"counter": "browser_tab_new_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}browser_tab_new 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.
Free to start. No card required.
Open a new tab. It is categorised as a Execute tool in the Playwright MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Playwright MCP server in PolicyLayer and add a rule for browser_tab_new: 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 Playwright MCP. Nothing to install.
browser_tab_new is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the browser_tab_new 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.
Set action: deny in the PolicyLayer policy for browser_tab_new. 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.
browser_tab_new is provided by the Playwright MCP server (korwabs/playwright-record-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Playwright MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
32 Playwright MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.