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browser_localstorage_clear

browser_localstorage_clear

How to control browser_localstorage_clear ↓

What browser_localstorage_clear does on Playwright

AI agents call browser_localstorage_clear to permanently remove resources in Playwright — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.

Critical Risk

Why browser_localstorage_clear needs a policy

The name strongly suggests this tool clears all localStorage for a browser origin, which is an irreversible bulk deletion of stored data. Given the Playwright context (browser automation) and sibling tools like browser_cookie_clear and browser_cookie_delete that confirm destructive patterns, this is almost certainly a destructive operation that cannot be undone.

From the tool's definition Tool name: browser_localstorage_clear — 'clear' implies irreversible removal of all localStorage data; description is empty, lowering confidence slightly

Documented attack patterns abuse exactly the kind of access browser_localstorage_clear gives an agent:

How to control browser_localstorage_clear

PolicyLayer is an MCP gateway — it sits between your AI agents and Playwright, and nothing reaches the server without passing your rules. This is the rule we recommend for browser_localstorage_clear:

policy.json
{
  "version": "1",
  "default": "deny",
  "hide": [
    "browser_localstorage_clear"
  ]
}

browser_localstorage_clear disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

  1. Create a free account and register Playwright — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
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Related tools and policies

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Questions about browser_localstorage_clear

What does the browser_localstorage_clear tool do? +

browser_localstorage_clear. It is categorised as a Destructive tool in the Playwright MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on browser_localstorage_clear? +

Register the Playwright MCP server in PolicyLayer and add a rule for browser_localstorage_clear: 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. Nothing to install.

What risk level is browser_localstorage_clear? +

browser_localstorage_clear is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit browser_localstorage_clear? +

Yes. Add a rate_limit block to the browser_localstorage_clear 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.

How do I block browser_localstorage_clear completely? +

Set action: deny in the PolicyLayer policy for browser_localstorage_clear. 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.

What MCP server provides browser_localstorage_clear? +

browser_localstorage_clear is provided by the Playwright MCP server (@playwright/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Playwright tool call.

Start from Playwright, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

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68 Playwright tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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