actions, querystrings, and arrays

[ashic]

I have an endpoint that looks something like:

http://example.com?foo=1&foo=2&foo=3

This would pass 1, 2, and 3 for foo, and on the server side, it'd bind to an array named foo. What would be the recommended way to represent this as an action? Currently I have:

{
            "name": "something",
            "href": "/__api/something",
            "title": "Do something with foo parameters",
            "method": "GET",
            "fields": [
                {
                    "name": "foo",
                    "title": "List of foos",
                    "type": "text"
                }
            ]
}

But this feels off as there's nothing signalling that foo can be an array.