create_catalog_variable · ServiceNow- MCP: Risk & Policy

WHAT IT DOES

What create_catalog_variable does on ServiceNow-MCP

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

WHY IT NEEDS A POLICY

Why create_catalog_variable needs a policy

This tool creates new catalog variables (form fields) which modifies the service catalog configuration. This is reversible (variables can be deleted or modified), making it a Write operation rather than Destructive.

From the tool's definition Tool name 'create_catalog_variable' combined with description '[Write] Add a form variable to a service catalog item' directly indicates creation of new data in ServiceNow's service catalog.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_catalog_variable Rate-limited

create_catalog_variable 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": {
    "create_catalog_variable": {
      "limits": [
        {
          "counter": "create_catalog_variable_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 ServiceNow-MCP, so you can run agents against it safely.

FAQ

Questions about create_catalog_variable

What does the create_catalog_variable tool do? +

[Write] Add a form variable to a service catalog item. It is categorised as a Write tool in the ServiceNow-MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_catalog_variable? +

Register the ServiceNow- MCP server in PolicyLayer and add a rule for create_catalog_variable: 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 ServiceNow-MCP. Nothing to install.

What risk level is create_catalog_variable? +

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

Can I rate-limit create_catalog_variable? +

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

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

create_catalog_variable is provided by the ServiceNow- MCP server (tedorigawa001/servicenow-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.