snow_create_uib_client_script · Serac MCP: Risk & Policy

WHAT IT DOES

What snow_create_uib_client_script does on Serac

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

WHY IT NEEDS A POLICY

Why snow_create_uib_client_script needs a policy

This tool creates new JavaScript code artifacts in ServiceNow's UI Builder, which is reversible (can be deleted/updated later) but has high blast radius because malicious client-side scripts can steal data, manipulate forms, inject keyloggers, or compromise user sessions across ServiceNow instances.

From the tool's definition Tool name 'snow_create_uib_client_script' explicitly states 'create'; description confirms it creates 'client-side JavaScript for UI Builder pages'. This is a create operation that modifies ServiceNow UI state.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

snow_create_uib_client_script Rate-limited

snow_create_uib_client_script 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": {
    "snow_create_uib_client_script": {
      "limits": [
        {
          "counter": "snow_create_uib_client_script_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 Serac, so you can run agents against it safely.

FAQ

Questions about snow_create_uib_client_script

What does the snow_create_uib_client_script tool do? +

Create client-side JavaScript for UI Builder pages. It is categorised as a Write tool in the Serac MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on snow_create_uib_client_script? +

Register the Serac MCP server in PolicyLayer and add a rule for snow_create_uib_client_script: 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 Serac. Nothing to install.

What risk level is snow_create_uib_client_script? +

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

Can I rate-limit snow_create_uib_client_script? +

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

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

snow_create_uib_client_script is provided by the Serac MCP server (serac-labs/serac). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.