browser_cookie_list
AI agents call browser_cookie_list to retrieve information from Playwright MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves cookie data from the browser without side effects. Listing cookies is a read-only operation that does not modify, delete, or execute code. Even though cookies can contain sensitive data, the tool itself performs no destructive or executable action—it only exposes existing data for inspection. Low severity due to limited blast radius if misused by an agent.
From the tool's definition Tool name 'browser_cookie_list' indicates listing/retrieving cookies; no modification or deletion verbs present. Consistent with sibling tools like 'browser_cookie_get' (read) vs 'browser_cookie_set'/'browser_cookie_delete' (write/destructive).
Attacks that exploit this kind of access
browser_cookie_list. It is categorised as a Read tool in the Playwright MCP MCP Server, which means it retrieves data without modifying state.
Register the Playwright MCP server in PolicyLayer and add a rule for browser_cookie_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 Playwright MCP. Nothing to install.
browser_cookie_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_cookie_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_cookie_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_cookie_list is provided by the Playwright MCP server (roshan571/playwright-mcp2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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