clear_session

THE RISK

Critical Risk

Why clear_session needs a policy

Clearing a saved session is irreversible: the authentication session data is destroyed and cannot be recovered. The user would need to log in again. Closing the browser also terminates any in-progress state. This is a destructive operation on session data, though the blast radius is moderate (limited to session/auth state, not financial data or files).

From the tool's definition 'Clears the saved session and closes the browser' — permanently removes the saved session state

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

POLICY

How to control clear_session

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

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "clear_session"
  ]
}

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

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

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Frisco MCP tools

Financial finish_session Opens the browser at the checkout page so you can select a delivery time and pay. Destructive clear_cart Empties the Frisco cart using the site Destructive remove_item_from_cart Removes a specific product from the Frisco cart by name (partial match supported). Execute login Opens a visible Chromium browser to log in to Frisco manually. Run this first to establish Write add_items_to_cart Adds products to cart by selecting from the most recent search_products result page. No ad Write update_item_quantity Changes the quantity of a product already in the cart (partial name match supported). Read check_cart_issues Checks the cart for sold-out or unavailable products and lists available substitutes for e Read get_logs Returns persisted JSONL log events for the current or selected session.

All 15 Frisco MCP tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in Frisco MCP → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about clear_session

What does the clear_session tool do? +

Clears the saved session and closes the browser. It is categorised as a Destructive tool in the Frisco MCP 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 clear_session? +

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

What risk level is clear_session? +

clear_session 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 clear_session? +

Yes. Add a rate_limit block to the clear_session 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 clear_session completely? +

Set action: deny in the PolicyLayer policy for clear_session. 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 clear_session? +

clear_session is provided by the Frisco MCP server (mkidawa/frisco-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Frisco MCP tool call.

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

CHECK YOUR STACK →