Enum-Extensions.cs

public static class EnumExtensions
{
    public static string Description(this Enum e)
		{
			var type = e.GetType();
			var name = Enum.GetName(type, e);

			var memberInfo = type.GetTypeInfo()
								 .DeclaredMembers
								 .Where(p => p.Name == name)
								 .FirstOrDefault();

			var attribute = memberInfo != null
				? memberInfo.GetCustomAttributes(true).Where(a => a.GetType() == typeof(DescriptionAttribute)).FirstOrDefault() as DescriptionAttribute
				: null;

			return attribute != null ? attribute.Description : name;
		}

		public static string Description(this IEnumerable<Enum> el, string separator = ",")
		{
			return String.Join(separator, el.Select(x => x.Description()));
		}
}