# zernio_create_custom_field

Create a new custom field for contacts.

Agent View of the PolicyLayer registry record for `zernio_create_custom_field`. HTML page: https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-create-custom-field

## Facts

- Tool: `zernio_create_custom_field`
- Server: Zernio (`eyalm321/zernio-mcp`) — https://policylayer.com/tools/eyalm321-zernio-mcp.md
- Homepage: https://github.com/Eyalm321/zernio-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

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

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

## Why zernio_create_custom_field is rated Medium

This tool creates (writes) a new custom field structure for contacts, which is a reversible action. It does not delete data (not Destructive), does not execute arbitrary code (not Execute), involves no financial transactions (not Financial), and produces side effects limited to schema extension.

From the tool's own definition: "Tool name contains 'create' and description states 'Create a new custom field for contacts' — a reversible data creation operation that modifies contact schema."

## Use case

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

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Zernio:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "zernio_create_custom_field": {
      "limits": [
        {
          "counter": "zernio_create_custom_field_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Zernio (273)

- `zernio_cancel_broadcast` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-cancel-broadcast.md
- `zernio_delete_account_group` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-account-group.md
- `zernio_delete_ad` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-ad.md
- `zernio_delete_api_key` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-api-key.md
- `zernio_delete_audience` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-audience.md
- `zernio_delete_automation` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-automation.md
- `zernio_delete_comment` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-comment.md
- `zernio_delete_contact` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-contact.md
- `zernio_delete_custom_field` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-custom-field.md
- `zernio_delete_gmb_media` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-gmb-media.md
- `zernio_delete_gmb_place_action` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-gmb-place-action.md
- `zernio_delete_instagram_ice_breakers` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-instagram-ice-breakers.md
- `zernio_delete_media` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-media.md
- `zernio_delete_message` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-message.md
- `zernio_delete_messenger_menu` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-messenger-menu.md
- `zernio_delete_post` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-post.md
- `zernio_delete_queue_slot` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-queue-slot.md
- `zernio_delete_review_reply` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-review-reply.md
- `zernio_delete_sequence` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-sequence.md
- `zernio_delete_telegram_commands` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-telegram-commands.md
- `zernio_delete_webhook` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-webhook.md
- `zernio_delete_whatsapp_contact` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-whatsapp-contact.md
- `zernio_delete_whatsapp_flow` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-whatsapp-flow.md
- `zernio_delete_whatsapp_group` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-whatsapp-group.md
- `zernio_delete_whatsapp_template` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-whatsapp-template.md
- `zernio_delete_zernio_profile` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-delete-zernio-profile.md
- `zernio_disconnect_account` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-disconnect-account.md
- `zernio_release_whatsapp_phone_number` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-release-whatsapp-phone-number.md
- `zernio_remove_user` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-remove-user.md
- `zernio_remove_whatsapp_group_participants` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-remove-whatsapp-group-participants.md
- …and 243 more: https://policylayer.com/tools/eyalm321-zernio-mcp.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`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=eyalm321-zernio-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/eyalm321-zernio-mcp