# deleteOneCalendarEventParticipant

A destructive tool on the Twenty MCP Server MCP server.

Agent View of the PolicyLayer registry record for `deleteOneCalendarEventParticipant`. HTML page: https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendareventparticipant

## Facts

- Tool: `deleteOneCalendarEventParticipant`
- Server: Twenty MCP Server (`jdu278/twenty-mcp-server`) — https://policylayer.com/tools/jdu278-twenty-mcp-server.md
- Homepage: https://github.com/Jdu278/twenty-mcp-server
- 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": "deleteOneCalendarEventParticipant",
    "arguments": {}
  }
}
```

## Why deleteOneCalendarEventParticipant is rated Critical

Deletion operations are irreversible and cannot be undone, placing this tool in the Destructive category. In a CRM context, removing calendar participants could disrupt meeting coordination and organizational records. The high severity reflects the potential for unintended removal of important scheduling data if an agent misuses this tool with incorrect identifiers.

From the tool's own definition: "Tool name contains 'deleteOne' and description states 'Delete One calendarEventParticipant' — explicit deletion operation that irreversibly removes calendar event participant data."

## Use case

AI agents call deleteOneCalendarEventParticipant to permanently remove resources in Twenty 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 Twenty MCP Server:

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

## Other tools on Twenty MCP Server (218)

- `deleteOneAttachment` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneattachment.md
- `deleteOneBlocklist` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneblocklist.md
- `deleteOneCalendarChannel` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarchannel.md
- `deleteOneCalendarChannelEventAssociation` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarchanneleventassociation.md
- `deleteOneCalendarEvent` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarevent.md
- `deleteOneCompany` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecompany.md
- `deleteOneConnectedAccount` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneconnectedaccount.md
- `deleteOneFavorite` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonefavorite.md
- `deleteOneFavoriteFolder` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonefavoritefolder.md
- `deleteOneMessage` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessage.md
- `deleteOneMessageChannel` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagechannel.md
- `deleteOneMessageChannelMessageAssociation` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagechannelmessageassociation.md
- `deleteOneMessageFolder` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagefolder.md
- `deleteOneMessageParticipant` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessageparticipant.md
- `deleteOneMessageThread` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagethread.md
- `deleteOneNote` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonenote.md
- `deleteOneNoteTarget` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonenotetarget.md
- `deleteOneOpportunity` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneopportunity.md
- `deleteOnePerson` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneperson.md
- `deleteOneTask` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetask.md
- `deleteOneTaskTarget` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetasktarget.md
- `deleteOneTimelineActivity` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetimelineactivity.md
- `deleteOneView` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneview.md
- `deleteOneViewField` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneviewfield.md
- `deleteOneViewFilter` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneviewfilter.md
- `deleteOneWorkflow` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflow.md
- `deleteOneWorkflowAutomatedTrigger` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowautomatedtrigger.md
- `deleteOneWorkflowRun` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowrun.md
- `deleteOneWorkflowVersion` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowversion.md
- `deleteOneWorkspaceMember` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkspacemember.md
- …and 188 more: https://policylayer.com/tools/jdu278-twenty-mcp-server.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=jdu278-twenty-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/jdu278-twenty-mcp-server