AI agents call browser_extract_table to retrieve information from Byob without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool extracts and reads table data from a webpage using CSS selectors. It performs a query-like operation on the DOM to retrieve structured data with no side effects—no modification of content, deletion of data, financial transactions, or command execution. The incomplete description suggests it only navigates and extracts table elements, consistent with a Read operation.
From the tool's definition Tool name 'browser_extract_table' and description 'Walk every <table> matching a CSS selector' indicate data retrieval from DOM tables without modification or execution of code.
Attacks that exploit this kind of access
Walk every <table> matching a CSS selector (default. It is categorised as a Read tool in the Byob MCP Server, which means it retrieves data without modifying state.
Register the Byob MCP server in PolicyLayer and add a rule for browser_extract_table: 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 Byob. Nothing to install.
browser_extract_table 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_extract_table 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_extract_table. 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_extract_table is provided by the Byob MCP server (wxtsky/byob). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.