# list_custom_fields

List custom field definitions in the workspace. Returns fields with their labels, types, and owner class info. Custom fields are created in the Huly UI on Card types, Issue types, or other classes. Use targetClass to filter fields for a specific class.

Agent View of the PolicyLayer registry record for `list_custom_fields`. HTML page: https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/list-custom-fields

## Facts

- Tool: `list_custom_fields`
- Server: Huly (`@firfi/huly-mcp`) — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp.md
- Install: `npx -y @firfi/huly-mcp`
- Homepage: https://github.com/dearlordylord/huly-mcp
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- 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": "list_custom_fields",
    "arguments": {}
  }
}
```

## Why list_custom_fields is rated Low

This tool retrieves metadata about custom field definitions in a workspace. It performs a query operation that returns information about field schemas and their associations with classes. There is no indication of data modification, deletion, or execution of external operations. The use of a filter parameter (targetClass) is typical of read operations and does not change this classification.

From the tool's own definition: "Tool description explicitly states 'List custom field definitions' and 'Returns fields with their labels, types, and owner class info.' The verb 'list' and 'returns' indicate data retrieval with no modification or side effects."

## Use case

AI agents call list_custom_fields to retrieve information from Huly 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 Huly:

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

## Other tools on Huly (517)

- `cancel_approval_request` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/cancel-approval-request.md
- `cancel_execution` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/cancel-execution.md
- `delete_activity_reply` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-activity-reply.md
- `delete_association` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-association.md
- `delete_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-attachment.md
- `delete_board_card` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-board-card.md
- `delete_board_label` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-board-label.md
- `delete_card` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-card.md
- `delete_card_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-card-comment.md
- `delete_channel` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-channel.md
- `delete_channel_message` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-channel-message.md
- `delete_chat_message_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-chat-message-attachment.md
- `delete_class_collaborator_metadata` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-class-collaborator-metadata.md
- `delete_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-comment.md
- `delete_component` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-component.md
- `delete_dm_message` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-dm-message.md
- `delete_document` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-document.md
- `delete_drawing` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drawing.md
- `delete_drive` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive.md
- `delete_drive_file_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive-file-comment.md
- `delete_drive_item` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-drive-item.md
- `delete_event` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-event.md
- `delete_huly_attribute` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-attribute.md
- `delete_huly_enum` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-enum.md
- `delete_huly_permission` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-permission.md
- `delete_huly_sequence` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-huly-sequence.md
- `delete_inventory_category` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-category.md
- `delete_inventory_product` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product.md
- `delete_inventory_product_attachment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product-attachment.md
- `delete_inventory_product_comment` — Destructive — https://policylayer.com/tools/io-github-dearlordylord-huly-mcp/delete-inventory-product-comment.md
- …and 487 more: https://policylayer.com/tools/io-github-dearlordylord-huly-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=io-github-dearlordylord-huly-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-dearlordylord-huly-mcp