add_to_cart · Cz Mtg Compare MCP: Risk & Policy

WHAT IT DOES

What add_to_cart does on Cz Mtg Compare

AI agents use add_to_cart to create or update resources in Cz Mtg Compare — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Cz Mtg Compare environment.

WHY IT NEEDS A POLICY

Why add_to_cart needs a policy

This tool creates or modifies a cart state (a Write action), which is reversible via 'clear_cart' or manual removal. It does not execute arbitrary code, delete data irreversibly, or commit financial transactions (no payment). The severity is medium because misuse could add unwanted items to a user's cart, potentially leading to accidental purchases, but the action is reversible before checkout.

From the tool's definition Tool name is 'add_to_cart' on an e-commerce server (MTG card price comparison with shop integration). The sibling tools include 'clear_cart', 'view_cart', and 'shop_login', confirming shopping cart functionality.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_to_cart Rate-limited

add_to_cart stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_to_cart": {
      "limits": [
        {
          "counter": "add_to_cart_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Cz Mtg Compare, so you can run agents against it safely.

FAQ

Questions about add_to_cart

What does the add_to_cart tool do? +

add_to_cart. It is categorised as a Write tool in the Cz Mtg Compare MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_to_cart? +

Register the Cz Mtg Compare MCP server in PolicyLayer and add a rule for add_to_cart: 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 Cz Mtg Compare. Nothing to install.

What risk level is add_to_cart? +

add_to_cart is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_to_cart? +

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

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

add_to_cart is provided by the Cz Mtg Compare MCP server (xvyslo05/czech-mtg-price-comparator-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.