using System;

using System.ComponentModel;

public class Program {

    public static void Main() => Console.WriteLine(BBCodes.Bold.Wrap("StackOverflow"));

}

​

public enum BBCodes {

    [Description("b")]

    Bold = 1,

    [Description("i")]

    Italic = 2

}

​

public static class BBCodesExt {

    public static string Wrap(this BBCodes code, string contents) => $"[{code.ToStringDescription()}]{contents}[/{code.ToStringDescription()}]";

    public static string ToStringDescription(this BBCodes code) {

        var attributes = (DescriptionAttribute[])code.GetType().GetField(code.ToString()).GetCustomAttributes(typeof(DescriptionAttribute), false);

        return attributes.Length > 0 ? attributes[0].Description : "";

    }

}