Query elements using CSS selector and get detailed information including text, attributes, position, and visibility.
AI agents call browser_query_selector to retrieve information from Playwright MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool retrieves and queries data about page elements without any side effects. It extracts information about DOM elements (text, attributes, position, visibility) but does not modify content, execute code, interact with elements, or trigger external operations. This is a standard Read operation equivalent to inspection/inspection queries.
From the tool's definition Tool description states it 'Query elements using CSS selector and get detailed information including text, attributes, position, and visibility' — this is purely informational retrieval with no modification or execution capability.
Attacks that exploit this kind of access
Query elements using CSS selector and get detailed information including text, attributes, position, and visibility. It is categorised as a Read tool in the Playwright MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Playwright MCP Server MCP server in PolicyLayer and add a rule for browser_query_selector: 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 Server. Nothing to install.
browser_query_selector 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_query_selector 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_query_selector. 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_query_selector is provided by the Playwright MCP Server MCP server (leviathangk/playwrightmcpforcrawler). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
browser_query_selector is one line of Playwright MCP Server's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
Teams ship this data inside their own products. See what a licence covers →