vtex_add_coupon_to_cart · MCP VTEX Server MCP: Risk & Policy

WHAT IT DOES

What vtex_add_coupon_to_cart does on MCP VTEX Server

AI agents use vtex_add_coupon_to_cart to create or update resources in MCP VTEX Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP VTEX Server environment.

WHY IT NEEDS A POLICY

Why vtex_add_coupon_to_cart needs a policy

This is a Write operation because it modifies cart data reversibly. While coupons affect pricing/discounts, the tool itself does not process payments or commit financial transactions—it only adds a promotional code to a cart. Severity is medium because misuse could apply unauthorized discounts to orders, affecting revenue, but the action is reversible and limited to cart scope (not yet finalized payment).

From the tool's definition Tool name is 'vtex_add_coupon_to_cart' and description states 'Add a coupon code to cart'. This modifies cart state by adding a coupon, which creates or alters a reversible data structure (the shopping cart with applied promotional codes).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

vtex_add_coupon_to_cart Rate-limited

vtex_add_coupon_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": {
    "vtex_add_coupon_to_cart": {
      "limits": [
        {
          "counter": "vtex_add_coupon_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 MCP VTEX Server, so you can run agents against it safely.

FAQ

Questions about vtex_add_coupon_to_cart

What does the vtex_add_coupon_to_cart tool do? +

Add a coupon code to cart. It is categorised as a Write tool in the MCP VTEX Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on vtex_add_coupon_to_cart? +

Register the MCP VTEX Server MCP server in PolicyLayer and add a rule for vtex_add_coupon_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 MCP VTEX Server. Nothing to install.

What risk level is vtex_add_coupon_to_cart? +

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

Can I rate-limit vtex_add_coupon_to_cart? +

Yes. Add a rate_limit block to the vtex_add_coupon_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 vtex_add_coupon_to_cart completely? +

Set action: deny in the PolicyLayer policy for vtex_add_coupon_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 vtex_add_coupon_to_cart? +

vtex_add_coupon_to_cart is provided by the MCP VTEX Server MCP server (leosepulveda/mcp-vtex). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.