# list_event_instances

Expands one recurring event (the series master id) into its individual instances, each with its own id (like masterId_20260901T100000Z) and concrete start/end. Use an instance id with update_event to reschedule a single occurrence, or with delete_event to cancel just that one; exceptions already made to the series show their changed times here. show_deleted=true includes cancelled occurrences. Bound the window with time_min/time_max — an unbounded infinite series is paginated via page_token.

Agent View of the PolicyLayer registry record for `list_event_instances`. HTML page: https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/list-event-instances

## Facts

- Tool: `list_event_instances`
- Server: Mcp Google Calendar (`@a1-x-tech/mcp-google-calendar`) — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar.md
- Install: `npx -y @a1-x-tech/mcp-google-calendar`
- Homepage: https://github.com/A1-x-Tech/mcp-google-calendar
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 8 (2 required)
- Recommended policy verdict: Allowed

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `event_id` | string | yes | The recurring series master id (from list_events without single_events). |
| `time_max` | string | no | Only instances starting before this RFC3339 moment. |
| `time_min` | string | no | Only instances ending at/after this RFC3339 moment. |
| `time_zone` | string | no | IANA zone the response times are rendered in. |
| `page_token` | string | no | nextPageToken from the previous page. |
| `calendar_id` | string | yes | The calendar id from list_calendars, or "primary" for the authenticated user's main calendar. |
| `max_results` | integer | no | Max instances per page (1..2500). |
| `show_deleted` | boolean | no | Include cancelled instances (status=cancelled). |

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": "list_event_instances",
    "arguments": {
      "event_id": "<event_id>",
      "calendar_id": "<calendar_id>"
    }
  }
}
```

## Why list_event_instances is rated Low

Even though list_event_instances only reads data, uncontrolled read access leaks sensitive information and racks up API costs: an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.

## Use case

AI agents call list_event_instances to retrieve information from Mcp Google Calendar 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 Mcp Google Calendar:

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

## Other tools on Mcp Google Calendar (18)

- `delete_event` — Destructive — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/delete-event.md
- `logout` — Destructive — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/logout.md
- `start_login` — Execute — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/start-login.md
- `auth_status` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/auth-status.md
- `get_calendar` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/get-calendar.md
- `get_event` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/get-event.md
- `list_calendars` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/list-calendars.md
- `list_events` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/list-events.md
- `query_free_busy` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/query-free-busy.md
- `raw_request` — Read — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/raw-request.md
- `create_event` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/create-event.md
- `create_focus_time` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/create-focus-time.md
- `create_out_of_office` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/create-out-of-office.md
- `finish_login` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/finish-login.md
- `move_event` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/move-event.md
- `set_client` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/set-client.md
- `setup_instructions` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/setup-instructions.md
- `update_event` — Write — https://policylayer.com/tools/a1-x-tech-mcp-google-calendar/update-event.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=a1-x-tech-mcp-google-calendar · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/a1-x-tech-mcp-google-calendar