update_discount_code · Shopify Graphql MCP: Risk & Policy

WHAT IT DOES

What update_discount_code does on Shopify Graphql

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

WHY IT NEEDS A POLICY

Why update_discount_code needs a policy

Updating discount codes is a reversible write operation that modifies store pricing rules and promotional offers. While not destructive (codes can be reverted) or financial (doesn't move money directly), it can significantly impact revenue by altering discount terms.

From the tool's definition Tool name 'update_discount_code' with description 'Update an existing discount code' indicates modification of discount configuration.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_discount_code Rate-limited

update_discount_code 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": {
    "update_discount_code": {
      "limits": [
        {
          "counter": "update_discount_code_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 Shopify Graphql, so you can run agents against it safely.

FAQ

Questions about update_discount_code

What does the update_discount_code tool do? +

Update an existing discount code. It is categorised as a Write tool in the Shopify Graphql MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_discount_code? +

Register the Shopify Graphql MCP server in PolicyLayer and add a rule for update_discount_code: 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 Shopify Graphql. Nothing to install.

What risk level is update_discount_code? +

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

Can I rate-limit update_discount_code? +

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

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

update_discount_code is provided by the Shopify Graphql MCP server (uvu-store/shopify-graphql-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.