# modify_event

Modify an existing event in a Google Calendar

Agent View of the PolicyLayer registry record for `modify_event`. HTML page: https://policylayer.com/tools/3xcaffeine-mcp-server/modify-event

## Facts

- Tool: `modify_event`
- Server: VaultAssist (`3xcaffeine/mcp-server`) — https://policylayer.com/tools/3xcaffeine-mcp-server.md
- Homepage: https://github.com/3xcaffeine/mcp-server
- 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": "modify_event",
    "arguments": {}
  }
}
```

## Why modify_event is rated Medium

This tool modifies calendar events, which is a reversible operation (changes can be undone by modifying again or reverting to previous state). It does not delete data (Destructive), execute arbitrary code (Execute), move money (Financial), or retrieve data without side effects (Read).

From the tool's own definition: "Tool name 'modify_event' and description 'Modify an existing event in a Google Calendar' indicate creation or modification of data in a reversible manner."

## Use case

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

## Recommended policy (PolicyLayer)

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

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

## Other tools on VaultAssist (78)

- `batch_delete_gmail_emails` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/batch-delete-gmail-emails.md
- `clear_completed_tasks` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/clear-completed-tasks.md
- `delete_event` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/delete-event.md
- `delete_gmail_email` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/delete-gmail-email.md
- `delete_gmail_label` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/delete-gmail-label.md
- `delete_task` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/delete-task.md
- `delete_task_list` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/delete-task-list.md
- `memory_delete_entities` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/memory-delete-entities.md
- `memory_delete_observations` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/memory-delete-observations.md
- `memory_delete_relations` — Destructive — https://policylayer.com/tools/3xcaffeine-mcp-server/memory-delete-relations.md
- `roll_dice` — Other — https://policylayer.com/tools/3xcaffeine-mcp-server/roll-dice.md
- `sequentialthinking` — Other — https://policylayer.com/tools/3xcaffeine-mcp-server/sequentialthinking.md
- `about` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/about.md
- `debug_table_structure` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/debug-table-structure.md
- `echo` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/echo.md
- `get_doc_content` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-doc-content.md
- `get_drive_file_content` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-drive-file-content.md
- `get_event` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-event.md
- `get_events` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-events.md
- `get_form` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-form.md
- `get_form_response` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-form-response.md
- `get_page` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-page.md
- `get_page_thumbnail` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-page-thumbnail.md
- `get_presentation` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-presentation.md
- `get_spreadsheet_info` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-spreadsheet-info.md
- `get_task` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-task.md
- `get_task_list` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-task-list.md
- `get_user_info` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/get-user-info.md
- `inspect_doc_structure` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/inspect-doc-structure.md
- `list_calendars` — Read — https://policylayer.com/tools/3xcaffeine-mcp-server/list-calendars.md
- …and 48 more: https://policylayer.com/tools/3xcaffeine-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`

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Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=3xcaffeine-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/3xcaffeine-mcp-server