When attempting to access the \'.box\' class of the $container, using (this) inside of the ajax call doesn\'t work.
$container.on(
\"click\",
You're close. 'this' in the context you are using it, refers to the ajax request rather than the thing that issued the event. To fix this, store a copy of this before making the ajax request:
}else{
var me = this;
$.ajax({
...
success: function(data){
description = data[0];
$(me).css('width', '70%');