dotnet-graphql override AddField, get register type's description attribute and set FieldType

MyObjectType.cs

public class MyObjectType : ObjectGraphType<MyObject>
    {
        public MyObjectType()
        {
            Field(t => t.Code);
        }
        public override FieldType AddField(FieldType fieldType)
        {
            //var type_ = fieldType.Resolver.GetType().GetTypeInfo().GenericTypeArguments[0];
            Type type = fieldType.Resolver.GetType().GetGenericArguments()[0];

            string description = type.GetProperty(fieldType.Name).GetCustomAttribute<DescriptionAttribute>().Description;
            fieldType.Description = description;

            return base.AddField(fieldType);
        }
    }