# create-data-type

Creates a new data type * CRITICAL WORKFLOW REQUIREMENT * BEFORE creating any new data type, you MUST perform the following steps: 1. First use the find-data-type function to search for existing data types with similar names and/or property editors 2. Verify if an existing data type can satisfy the requirements 3. Only proceed with creating a new data type if no suitable option exists 4. If a similar data type exists, inform the user and suggest using this one instead. * PROPERTY EDITOR CONFIGURATION * When creating a new data type you will need to assign a property editor with the correct configuration. IMPORTANT: Use the get-data-type-schema tool to: - Get the JSON Schema for an existing data type by its Id to understand its configuration structure - Or use get-data-type-schemas to fetch schemas for multiple data types in a batch - The schema describes the expected value structure for the property editor * VALIDATION * If you are not asked for a property editor then stop and ask the user to provide one. If you are asked to create a data type for a property that already exists, then stop and ask the user to provide a unique name.

Agent View of the PolicyLayer registry record for `create-data-type`. HTML page: https://policylayer.com/tools/mcp-dev/create-data-type

## Facts

- Tool: `create-data-type`
- Server: Mcp Dev (`@umbraco-cms/mcp-dev`) — https://policylayer.com/tools/mcp-dev.md
- Install: `npx -y @umbraco-cms/mcp-dev`
- Homepage: git+https://github.com/umbraco/Umbraco-CMS-MCP-Dev.git
- 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": "create-data-type",
    "arguments": {}
  }
}
```

## Why create-data-type is rated Medium

This tool creates new data types in Umbraco CMS, which are structural/configuration objects that define how content properties behave. This is a write operation that adds new persistent data to the system. While reversible (data types can be deleted), creation of CMS schema elements affects the system's data model and could impact existing content or workflows.

From the tool's own definition: "Creates a new data type - this is a create operation that modifies the Umbraco CMS configuration by adding new content type definitions."

## Use case

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

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "create-data-type": {
      "limits": [
        {
          "counter": "create-data-type_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Mcp Dev (418)

- `create-document-version-rollback` — Destructive — https://policylayer.com/tools/mcp-dev/create-document-version-rollback.md
- `delete-data-type` — Destructive — https://policylayer.com/tools/mcp-dev/delete-data-type.md
- `delete-data-type-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-data-type-folder.md
- `delete-dictionary-item` — Destructive — https://policylayer.com/tools/mcp-dev/delete-dictionary-item.md
- `delete-document` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document.md
- `delete-document-blueprint` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-blueprint.md
- `delete-document-blueprint-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-blueprint-folder.md
- `delete-document-public-access` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-public-access.md
- `delete-document-recycle-bin-item` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-recycle-bin-item.md
- `delete-document-type` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-type.md
- `delete-document-type-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-document-type-folder.md
- `delete-element` — Destructive — https://policylayer.com/tools/mcp-dev/delete-element.md
- `delete-element-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-element-folder.md
- `delete-element-folder-from-recycle-bin` — Destructive — https://policylayer.com/tools/mcp-dev/delete-element-folder-from-recycle-bin.md
- `delete-element-from-recycle-bin` — Destructive — https://policylayer.com/tools/mcp-dev/delete-element-from-recycle-bin.md
- `delete-from-recycle-bin` — Destructive — https://policylayer.com/tools/mcp-dev/delete-from-recycle-bin.md
- `delete-language` — Destructive — https://policylayer.com/tools/mcp-dev/delete-language.md
- `delete-log-viewer-saved-search-by-name` — Destructive — https://policylayer.com/tools/mcp-dev/delete-log-viewer-saved-search-by-name.md
- `delete-media` — Destructive — https://policylayer.com/tools/mcp-dev/delete-media.md
- `delete-media-from-recycle-bin` — Destructive — https://policylayer.com/tools/mcp-dev/delete-media-from-recycle-bin.md
- `delete-media-recycle-bin-item` — Destructive — https://policylayer.com/tools/mcp-dev/delete-media-recycle-bin-item.md
- `delete-media-type` — Destructive — https://policylayer.com/tools/mcp-dev/delete-media-type.md
- `delete-media-type-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-media-type-folder.md
- `delete-member` — Destructive — https://policylayer.com/tools/mcp-dev/delete-member.md
- `delete-member-group` — Destructive — https://policylayer.com/tools/mcp-dev/delete-member-group.md
- `delete-member-type` — Destructive — https://policylayer.com/tools/mcp-dev/delete-member-type.md
- `delete-partial-view` — Destructive — https://policylayer.com/tools/mcp-dev/delete-partial-view.md
- `delete-partial-view-folder` — Destructive — https://policylayer.com/tools/mcp-dev/delete-partial-view-folder.md
- `delete-redirect` — Destructive — https://policylayer.com/tools/mcp-dev/delete-redirect.md
- `delete-script` — Destructive — https://policylayer.com/tools/mcp-dev/delete-script.md
- …and 388 more: https://policylayer.com/tools/mcp-dev.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=mcp-dev · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/mcp-dev