Define your structure separately using a @typdef:
/**
* @typedef {Object} Point
* @property {number} x - The X Coordinate
* @property {number} y - The Y Coordinate
*/
And use it as the return type:
/**
* Returns a coordinate from a given mouse or touch event
* @param {TouchEvent|MouseEvent|jQuery.Event} e
* A valid mouse or touch event or a jQuery event wrapping such an
* event.
* @param {string} [type="page"]
* A string representing the type of location that should be
* returned. Can be either "page", "client" or "screen".
* @return {Point}
* The location of the event
*/
var getEventLocation = function(e, type) {
...
return {x: xLocation, y: yLocation};
}