# zernio_delete_custom_field

Delete a custom contact field.

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

## Facts

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

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

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

## Why zernio_delete_custom_field is rated Critical

Deleting a custom contact field removes data that cannot be recovered. While scoped to a single field rather than entire contacts or databases, the irreversible nature of deletion and potential impact on contact data management workflows (dependent fields, lost historical data) makes this Destructive. This is more severe than Write (which is reversible) and ranks highest among the available categories.

From the tool's own definition: "Tool name explicitly includes 'delete'; description states 'Delete a custom contact field' — this is an irreversible deletion operation."

## Use case

AI agents call zernio_delete_custom_field to permanently remove resources in Zernio, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "hide": [
    "zernio_delete_custom_field"
  ]
}
```

## 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_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
- `zernio_twitter_remove_bookmark` — Destructive — https://policylayer.com/tools/eyalm321-zernio-mcp/zernio-twitter-remove-bookmark.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`

---

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