# calendar_update_event

Update an existing event in Google Calendar. Can modify title, time, location, description, and attendees. Only specified fields will be updated.

Agent View of the PolicyLayer registry record for `calendar_update_event`. HTML page: https://policylayer.com/tools/io-github-saloprj-dialogbrain/calendar-update-event

## Facts

- Tool: `calendar_update_event`
- Server: Dialogbrain (`https://api.dialogbrain.com/mcp`) — https://policylayer.com/tools/io-github-saloprj-dialogbrain.md
- Homepage: https://github.com/saloprj/dialogbrain-mcp
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 8 (1 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `end` | string | no | New end time in ISO 8601 format. Optional. |
| `start` | string | no | New start time in ISO 8601 format. Optional. |
| `summary` | string | no | New event title/summary. Optional. |
| `event_id` | string | yes | ID of the event to update. Required. |
| `location` | string | no | New event location. Optional. |
| `attendees` | array | no | New list of attendee emails. Replaces existing attendees. |
| `calendar_id` | string | no | Calendar ID containing the event. Defaults to primary. |
| `description` | string | no | New event description. Optional. |

Parameters from the server's own tool schema.

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "calendar_update_event",
    "arguments": {
      "event_id": "<event_id>"
    }
  }
}
```

## Why calendar_update_event is rated Medium

This tool modifies existing calendar events but does not delete or destroy data, making it Write rather than Destructive. The severity is medium because misuse could cause scheduling confusion, missed meetings, or unintended attendee changes, but effects are reversible by re-editing the event. Confidence is high because the description clearly indicates data modification without irreversible side effects.

From the tool's own definition: "'Update an existing event in Google Calendar. Can modify title, time, location, description, and attendees.' This describes reversible modification of calendar data."

## Use case

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

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "calendar_update_event": {
      "limits": [
        {
          "counter": "calendar_update_event_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Dialogbrain (221)

- `agents_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/agents-delete.md
- `agents_trigger_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/agents-trigger-delete.md
- `ai_filters_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/ai-filters-delete.md
- `ai_tags_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/ai-tags-delete.md
- `calendar_delete_event` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/calendar-delete-event.md
- `collections_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/collections-delete.md
- `files_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/files-delete.md
- `folders_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/folders-delete.md
- `integrations_remove_endpoints` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/integrations-remove-endpoints.md
- `messages_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/messages-delete.md
- `notes_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/notes-delete.md
- `reminder_cancel` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/reminder-cancel.md
- `tasks_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/tasks-delete.md
- `threads_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/threads-delete.md
- `widgets_delete` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/widgets-delete.md
- `youtube_delete_comment` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/youtube-delete-comment.md
- `youtube_delete_video` — Destructive — https://policylayer.com/tools/io-github-saloprj-dialogbrain/youtube-delete-video.md
- `agent_handoff` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/agent-handoff.md
- `agents_ask` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/agents-ask.md
- `agents_simulate_inbound` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/agents-simulate-inbound.md
- `android_launch_app` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/android-launch-app.md
- `android_shell` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/android-shell.md
- `android_ui_dump` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/android-ui-dump.md
- `background_run` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/background-run.md
- `browser_attach_meet` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-attach-meet.md
- `browser_click` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-click.md
- `browser_close` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-close.md
- `browser_drag` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-drag.md
- `browser_evaluate` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-evaluate.md
- `browser_fill` — Execute — https://policylayer.com/tools/io-github-saloprj-dialogbrain/browser-fill.md
- …and 191 more: https://policylayer.com/tools/io-github-saloprj-dialogbrain.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=io-github-saloprj-dialogbrain · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-saloprj-dialogbrain
