# compare_instances

Compare two configured ServiceNow instances: record counts for a table (with optional query) and/or a specific system property value. Useful for dev→prod drift detection and governance.

Agent View of the PolicyLayer registry record for `compare_instances`. HTML page: https://policylayer.com/tools/servicenow-mcp-server/compare-instances

## Facts

- Tool: `compare_instances`
- Server: ServiceNow MCP Server (`@aartiq/servicenow-mcp`) — https://policylayer.com/tools/servicenow-mcp-server.md
- Install: `npx -y @aartiq/servicenow-mcp`
- Homepage: https://github.com/aartiq/servicenow-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity verified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "compare_instances",
    "arguments": {}
  }
}
```

## Why compare_instances is rated Low

The tool performs read-only queries against ServiceNow instances to gather comparative data (counts and property values). It has no capability to modify, delete, execute, or trigger financial operations. The worst-case misuse would be information disclosure about system configuration differences, which is a low-severity Read operation.

From the tool's own definition: "Tool description states it 'Compare[s]' and retrieves 'record counts' and 'system property value[s]' without any indication of modification, deletion, or execution of side-effecting operations."

## Use case

AI agents call compare_instances to retrieve information from ServiceNow MCP Server without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches ServiceNow MCP Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "compare_instances": {}
  }
}
```

## Other tools on ServiceNow MCP Server (414)

- `cmdb_reconcile` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/cmdb-reconcile.md
- `delete_attachment` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/delete-attachment.md
- `delete_record` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/delete-record.md
- `delete_system_property` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/delete-system-property.md
- `delete_uib_page` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/delete-uib-page.md
- `remove_user_from_group` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/remove-user-from-group.md
- `rollback_changes` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/rollback-changes.md
- `rollback_deployment` — Destructive — https://policylayer.com/tools/servicenow-mcp-server/rollback-deployment.md
- `batch_request` — Execute — https://policylayer.com/tools/servicenow-mcp-server/batch-request.md
- `categorize_incident` — Execute — https://policylayer.com/tools/servicenow-mcp-server/categorize-incident.md
- `commit_changeset` — Execute — https://policylayer.com/tools/servicenow-mcp-server/commit-changeset.md
- `create_business_rule` — Execute — https://policylayer.com/tools/servicenow-mcp-server/create-business-rule.md
- `create_flow_action` — Execute — https://policylayer.com/tools/servicenow-mcp-server/create-flow-action.md
- `create_scheduled_job` — Execute — https://policylayer.com/tools/servicenow-mcp-server/create-scheduled-job.md
- `create_script_include` — Execute — https://policylayer.com/tools/servicenow-mcp-server/create-script-include.md
- `create_ui_action` — Execute — https://policylayer.com/tools/servicenow-mcp-server/create-ui-action.md
- `execute_background_script` — Execute — https://policylayer.com/tools/servicenow-mcp-server/execute-background-script.md
- `execute_playbook` — Execute — https://policylayer.com/tools/servicenow-mcp-server/execute-playbook.md
- `execute_script` — Execute — https://policylayer.com/tools/servicenow-mcp-server/execute-script.md
- `fire_event` — Execute — https://policylayer.com/tools/servicenow-mcp-server/fire-event.md
- `fluent_build` — Execute — https://policylayer.com/tools/servicenow-mcp-server/fluent-build.md
- `fluent_explain` — Execute — https://policylayer.com/tools/servicenow-mcp-server/fluent-explain.md
- `fluent_init` — Execute — https://policylayer.com/tools/servicenow-mcp-server/fluent-init.md
- `fluent_validate` — Execute — https://policylayer.com/tools/servicenow-mcp-server/fluent-validate.md
- `ml_detect_anomalies` — Execute — https://policylayer.com/tools/servicenow-mcp-server/ml-detect-anomalies.md
- `ml_train_anomaly_detector` — Execute — https://policylayer.com/tools/servicenow-mcp-server/ml-train-anomaly-detector.md
- `ml_train_change_risk` — Execute — https://policylayer.com/tools/servicenow-mcp-server/ml-train-change-risk.md
- `ml_train_incident_classifier` — Execute — https://policylayer.com/tools/servicenow-mcp-server/ml-train-incident-classifier.md
- `publish_changeset` — Execute — https://policylayer.com/tools/servicenow-mcp-server/publish-changeset.md
- `run_aggregate_query` — Execute — https://policylayer.com/tools/servicenow-mcp-server/run-aggregate-query.md
- …and 384 more: https://policylayer.com/tools/servicenow-mcp-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=servicenow-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/servicenow-mcp-server