# custom_delete_custom_object_type_fields

[CUSTOM] Calls the Marketo REST API directly (not Adobe's native MCP).

Agent View of the PolicyLayer registry record for `custom_delete_custom_object_type_fields`. HTML page: https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-custom-object-type-fields

## Facts

- Tool: `custom_delete_custom_object_type_fields`
- Server: Marketo MCP Server (`tyron-pretorius/marketo-mcp`) — https://policylayer.com/tools/tyron-pretorius-marketo-mcp.md
- Homepage: https://github.com/tyron-pretorius/marketo-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": "custom_delete_custom_object_type_fields",
    "arguments": {}
  }
}
```

## Why custom_delete_custom_object_type_fields is rated Critical

The 'delete' action is inherently destructive and irreversible. Deleting custom object type fields in a marketing automation system like Marketo will permanently remove those field definitions and associated data, affecting campaigns, leads, and program configurations that depend on those fields. This cannot be easily undone and has high blast radius if triggered incorrectly by an AI agent.

From the tool's own definition: "Tool name contains 'delete' and 'fields', indicating irreversible removal of custom object type field definitions. Description states it 'Calls the Marketo REST API directly,' which is a pass-through for API operations that modify Marketo data structures."

## Use case

AI agents call custom_delete_custom_object_type_fields to permanently remove resources in Marketo MCP Server, 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 Marketo MCP Server:

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

## Other tools on Marketo MCP Server (297)

- `custom_cancel_lead_export_job` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-cancel-lead-export-job.md
- `custom_delete_companies` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-companies.md
- `custom_delete_custom_activity_type` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-custom-activity-type.md
- `custom_delete_custom_activity_type_attributes` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-custom-activity-type-attributes.md
- `custom_delete_custom_object_type` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-custom-object-type.md
- `custom_delete_custom_objects` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-custom-objects.md
- `custom_delete_email` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-email.md
- `custom_delete_email_module` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-email-module.md
- `custom_delete_email_template` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-email-template.md
- `custom_delete_email_template2` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-email-template2.md
- `custom_delete_email2` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-email2.md
- `custom_delete_folder` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-folder.md
- `custom_delete_form` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-form.md
- `custom_delete_form_field` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-form-field.md
- `custom_delete_form_fieldset_field` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-form-fieldset-field.md
- `custom_delete_fragment` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-fragment.md
- `custom_delete_landing_page` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-landing-page.md
- `custom_delete_landing_page_content_section` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-landing-page-content-section.md
- `custom_delete_landing_page_template` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-landing-page-template.md
- `custom_delete_leads` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-leads.md
- `custom_delete_named_account_lists` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-named-account-lists.md
- `custom_delete_named_accounts` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-named-accounts.md
- `custom_delete_opportunities` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-opportunities.md
- `custom_delete_opportunity_roles` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-opportunity-roles.md
- `custom_delete_program` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-program.md
- `custom_delete_program_members` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-program-members.md
- `custom_delete_redirect_rule` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-redirect-rule.md
- `custom_delete_sales_persons` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-sales-persons.md
- `custom_delete_smart_campaign` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-smart-campaign.md
- `custom_delete_smart_list` — Destructive — https://policylayer.com/tools/tyron-pretorius-marketo-mcp/custom-delete-smart-list.md
- …and 267 more: https://policylayer.com/tools/tyron-pretorius-marketo-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=tyron-pretorius-marketo-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/tyron-pretorius-marketo-mcp
