Reading Custom Attributes of a .Net class property in Javascript

I have a .Net class with some properties. In some of the properties, I use Custom Attributes. For e.g.

   <UserDefined(true)>_
   Property Name as string

I Use webservices and JSON to retrieve an instance of this class on my web-forms client side and use Java-script extensively. Is there a way in Java-script object to identify whether a Property has any Custom Attribute defined and its value? I tried Property Description of the Object class in JS, but it just gives the property name and its value, not any Attributes of that Property.