Detect ArcGIS REST API layer type

LayerTypeDetector.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Web.Script.Serialization;

namespace LayerTypeDetector
{
    class Program
    {
        static void Main(string[] args)
        {
            WebRequest request;
            WebResponse response;
            var serializer = new JavaScriptSerializer();

            for (int i = 0, l = args.Length; i < l; i++)
            {
                UriBuilder builder = new UriBuilder(args[i]);
                builder.Query = "f=json";
                request = WebRequest.Create(builder.Uri);
                response = request.GetResponse();
                using (StreamReader reader = new StreamReader(response.GetResponseStream()))
                {
                    var dict = serializer.Deserialize<Dictionary<string, object>>(reader.ReadToEnd());
                    if (dict.Keys.Contains("tileInfo"))
                    {
                        Console.WriteLine("\"{0}\" is a tiled map service.", builder.Uri);
                    }
                    else
                    {
                        Console.WriteLine("\"{0}\" is not a tiled map service.", builder.Uri);
                    }
                }
                
            }
        }
    }
}