browser_localstorage_list
AI agents call browser_localstorage_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 or enumerates local storage entries in a browser session, allowing inspection of stored data. It has no side effects—it queries state without modifying, deleting, or executing code. Even though it could expose sensitive data stored by web applications, the capability itself is a read operation.
From the tool's definition Tool name 'browser_localstorage_list' indicates a listing/enumeration operation on browser local storage. The 'list' verb suggests querying or retrieving stored data without modification.
Attacks that exploit this kind of access
browser_localstorage_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_localstorage_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_localstorage_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_localstorage_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_localstorage_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_localstorage_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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