update_script_tag · Shopify Graphql MCP: Risk & Policy

WHAT IT DOES

What update_script_tag does on Shopify Graphql

AI agents use update_script_tag 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_script_tag needs a policy

This tool modifies existing data (script tags) reversibly without deleting it. However, the high severity reflects that script tags execute arbitrary code in the storefront environment, creating significant risk if an AI agent injects malicious JavaScript. While categorized as Write (data modification), the blast radius approaches Execute-level danger due to code injection potential.

From the tool's definition Tool name 'update_script_tag' and description 'Update an existing script tag' indicate modification of stored configuration. Script tags in Shopify control JavaScript injected into storefronts, affecting customer-facing functionality.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_script_tag Rate-limited

update_script_tag 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_script_tag": {
      "limits": [
        {
          "counter": "update_script_tag_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_script_tag

What does the update_script_tag tool do? +

Update an existing script tag. 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_script_tag? +

Register the Shopify Graphql MCP server in PolicyLayer and add a rule for update_script_tag: 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_script_tag? +

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

Can I rate-limit update_script_tag? +

Yes. Add a rate_limit block to the update_script_tag 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_script_tag completely? +

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

update_script_tag 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.