# list_calendars

List writable, non-hidden calendars that can be used as create_event or create_recurring_event targets. Use this before creating events when you need to choose a target calendarId explicitly.

Agent View of the PolicyLayer registry record for `list_calendars`. HTML page: https://policylayer.com/tools/dugynoo-huly-mcp/list-calendars

## Facts

- Tool: `list_calendars`
- Server: Huly (`dugynoo/huly-mcp`) — https://policylayer.com/tools/dugynoo-huly-mcp.md
- Homepage: https://github.com/dugynoo/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_calendars",
    "arguments": {}
  }
}
```

## Why list_calendars is rated Low

This tool retrieves and queries calendar metadata without creating, modifying, or deleting any data. It is purely informational, used to enumerate available calendars. The fact that it filters for 'writable, non-hidden' calendars is a descriptive filter, not a modification. The tool does not perform any irreversible or state-changing actions—it simply returns information to aid in subsequent decisions.

From the tool's own definition: "Tool description states it 'List[s]' calendars and is used to query available calendars before performing write operations. The verb 'list' is a read-only operation with no side effects."

## Use case

AI agents call list_calendars 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_calendars": {}
  }
}
```

## Other tools on Huly (217)

- `dedup_planner_todos` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/dedup-planner-todos.md
- `delete_attachment` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-attachment.md
- `delete_card` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-card.md
- `delete_channel` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-channel.md
- `delete_channel_message` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-channel-message.md
- `delete_comment` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-comment.md
- `delete_component` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-component.md
- `delete_dm_message` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-dm-message.md
- `delete_document` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-document.md
- `delete_event` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-event.md
- `delete_issue` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-issue.md
- `delete_issue_template` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-issue-template.md
- `delete_label` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-label.md
- `delete_milestone` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-milestone.md
- `delete_notification` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-notification.md
- `delete_organization` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-organization.md
- `delete_person` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-person.md
- `delete_project` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-project.md
- `delete_relation` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-relation.md
- `delete_tag_category` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-tag-category.md
- `delete_teamspace` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-teamspace.md
- `delete_test_case` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-test-case.md
- `delete_test_plan` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-test-plan.md
- `delete_test_result` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-test-result.md
- `delete_test_run` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-test-run.md
- `delete_test_suite` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-test-suite.md
- `delete_thread_reply` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-thread-reply.md
- `delete_workspace` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/delete-workspace.md
- `remove_issue_relation` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/remove-issue-relation.md
- `remove_organization_member` — Destructive — https://policylayer.com/tools/dugynoo-huly-mcp/remove-organization-member.md
- …and 187 more: https://policylayer.com/tools/dugynoo-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=dugynoo-huly-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/dugynoo-huly-mcp