Mirror API Custom menu item voice trigger

Question

I am currently developing an app for Glass using the Mirro API.

An example of a call to Google is (Raw HTTP):

POST /mirror/v1/timeline HTTP/1.1
Host: www.googleapis.com
Authorization: Bearer auth token
Content-Type: application/json
Content-Length: length

{
    "text": "Hello world",
    "menuItems": [
    { "action": "DELETE" },
    {
        "action": "CUSTOM",
        "id": "complete"
        "values": [{
            "displayName": "Complete",
            "iconUrl": "http://example.com/icons/complete.png"
        }]
    }
}

This results in a new card on my timeline. After receiving it, I can say "OK Glass" to enter the voice menu (This is only available directly after receiving the card). However, I only see delete as an option in this menu. Is it possible to add my custom menu items to the voice menu?

General information can be found here: https://developers.google.com/glass/v1/reference/timeline/insert I might have overlooked something.