Reflection ParameterInfo get attributes of a non-primitive type parameter

What i want to do is extract all the details of parameters for a particular MethodInfo object and save as a JSON formatted string. This JSON string will then be used as a template to create a parameter object to be passed to the method.

At the moment, i have this simple code

MethodInfo mi = //function which returns mi object. 
mi.GetParameters();

This will return the following:

{System.Reflection.ParameterInfo[3]}
[0]: {System.String user_id}
[1]: {System.String password}
[2]: {business_details bus_det}

GetParameters() does not return any details about the busienss_details class. Is there any way that i can get a breakdown of what it contains?