AI agents call browser_tab_list to retrieve information from Fast Playwright MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves information about open browser tabs (titles and URLs) without modifying, executing, or deleting anything. It is a passive read operation that gathers state information, making it the lowest-severity category. The confidence is high because the description is explicit and unambiguous about its read-only nature.
From the tool's definition Tool name 'browser_tab_list' and description 'List browser tabs with titles and URLs' indicate a retrieval operation with no side effects.
Documented attack patterns abuse exactly the kind of access browser_tab_list gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Fast Playwright MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_tab_list:
{
"version": "1",
"default": "deny",
"tools": {
"browser_tab_list": {}
}
}browser_tab_list is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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List browser tabs with titles and URLs. It is categorised as a Read tool in the Fast Playwright MCP MCP Server, which means it retrieves data without modifying state.
Register the Fast Playwright 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 Fast Playwright MCP. Nothing to install.
browser_tab_list is a Read tool with low risk. Read-only tools are generally safe to allow by default.
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.
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.
browser_tab_list is provided by the Fast Playwright MCP server (tontoko/fast-playwright-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 34 Fast Playwright MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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34 Fast Playwright MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.