switch_instance · ServiceNow- MCP: Risk & Policy

WHAT IT DOES

What switch_instance does on ServiceNow-MCP

AI agents use switch_instance 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 switch_instance needs a policy

This tool modifies the active context (instance) for the current session, which is a reversible state change but not a destructive operation or query. It's categorized as Write because it alters session configuration. Severity is medium because switching instances could cause subsequent operations to target an unintended environment (e.g., production vs. staging), potentially leading to unintended data modifications.

From the tool's definition Tool name 'switch_instance' and description 'Switch the active ServiceNow instance for this session' indicate a modification of session state that affects subsequent operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

switch_instance Rate-limited

switch_instance 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": {
    "switch_instance": {
      "limits": [
        {
          "counter": "switch_instance_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 switch_instance

What does the switch_instance tool do? +

Switch the active ServiceNow instance for this session. 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 switch_instance? +

Register the ServiceNow- MCP server in PolicyLayer and add a rule for switch_instance: 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 switch_instance? +

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

Can I rate-limit switch_instance? +

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

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

switch_instance 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.