# modify_booking

Change one of the signed-in user's bookings. Requires the 6-digit verificationCode from request_booking_action_code. Special-request edits always apply. A DATE change is pushed to the hotel supplier as a cancel-and-rebook at current availability, so it only works for suppliers that support amendment — for others (and when no room is available for the new dates) it returns an error asking you to cancel and rebook instead. A date change can shift the price and issue a new confirmation; the result's supplierModifyStatus says whether the supplier reservation was actually changed (modified), simulated (simulated), or the edit stayed local (local_only, e.g. special requests only). Never promise a date change went through unless supplierModifyStatus is modified or simulated.

Agent View of the PolicyLayer registry record for `modify_booking`. HTML page: https://policylayer.com/tools/com-getmyhotels-getmyhotels/modify-booking

## Facts

- Tool: `modify_booking`
- Server: GetMyHotels (`https://mcp.getmyhotels.com`) — https://policylayer.com/tools/com-getmyhotels-getmyhotels.md
- Homepage: https://github.com/fenilsonani/gmh
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server rate-limited: no
- Parameters: 5 (2 required)
- Recommended policy verdict: Rate-limited

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `checkIn` | string | no | New check-in date, ISO 8601 (optional). |
| `checkOut` | string | no | New check-out date, ISO 8601 (optional). |
| `publicId` | string | yes | The booking's public id. |
| `specialRequests` | string | no | New special requests (≤2000 chars, optional). |
| `verificationCode` | string | yes | 6-digit code from `request_booking_action_code`. |

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": "modify_booking",
    "arguments": {
      "publicId": "<publicId>",
      "verificationCode": "<verificationCode>"
    }
  }
}
```

## Why modify_booking is rated Medium

This tool modifies existing bookings (dates, prices, confirmations) in a reversible manner. While it affects financial records (price changes), the primary action is data modification rather than money movement. The 'modify' operation is typical Write behavior.

From the tool's own definition: "Tool description explicitly states it can 'Change one of the signed-in user's bookings' and mentions modifying dates which 'can shift the price and issue a new confirmation.' The description indicates modifications are reversible through cancel-and-rebook…"

## Use case

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

## Recommended policy (PolicyLayer)

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

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

## Other tools on GetMyHotels (17)

- `cancel_booking` — Destructive — https://policylayer.com/tools/com-getmyhotels-getmyhotels/cancel-booking.md
- `create_checkout` — Financial — https://policylayer.com/tools/com-getmyhotels-getmyhotels/create-checkout.md
- `create_one_click_checkout` — Financial — https://policylayer.com/tools/com-getmyhotels-getmyhotels/create-one-click-checkout.md
- `fetch` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/fetch.md
- `get_booking` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/get-booking.md
- `get_checkout_quote` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/get-checkout-quote.md
- `get_hotel_details` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/get-hotel-details.md
- `get_my_booking` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/get-my-booking.md
- `get_rooms` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/get-rooms.md
- `list_my_bookings` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/list-my-bookings.md
- `list_payment_methods` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/list-payment-methods.md
- `list_trips` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/list-trips.md
- `search` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/search.md
- `search_hotels` — Read — https://policylayer.com/tools/com-getmyhotels-getmyhotels/search-hotels.md
- `add_trip_item` — Write — https://policylayer.com/tools/com-getmyhotels-getmyhotels/add-trip-item.md
- `request_booking_action_code` — Write — https://policylayer.com/tools/com-getmyhotels-getmyhotels/request-booking-action-code.md
- `save_trip` — Write — https://policylayer.com/tools/com-getmyhotels-getmyhotels/save-trip.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=com-getmyhotels-getmyhotels · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-getmyhotels-getmyhotels