How does Arduino IDE 'Get Board Info'?

Looking at the source code of the Arduino IDE on github, it looks like they call an executable (listComPorts.exe). So I would guess you can't get that info through serial.

Here's a C# app using WMI that can get port, vid, and pid:

namespace PortTest
{
    class Program
    {
        // Helper function to handle regex search
        static string regex(string pattern, string text)
        {
            Regex re = new Regex(pattern);
            Match m = re.Match(text);
            if (m.Success)
            {
                return m.Value;
            }
            else
            {
                return null;
            }
        }

        static void Main(string[] args)
        {
            // Use WMI to get info
            ManagementObjectSearcher searcher = new ManagementObjectSearcher("root\\CIMV2",
                "SELECT * FROM Win32_PnPEntity WHERE ClassGuid=\"{4d36e978-e325-11ce-bfc1-08002be10318}\"");

            // Search all serial ports
            foreach (ManagementObject queryObj in searcher.Get())
            {
                // Parse the data
                if (null != queryObj["Name"])
                {
                    Console.WriteLine("Port = " + regex(@"(\(COM\d+\))", queryObj["Name"].ToString()));
                }
                //PNPDeviceID = USB\VID_1A86&PID_7523\5&1A63D808&0&2
                if (null != queryObj["PNPDeviceID"])
                {
                    Console.WriteLine("VID = " + regex("VID_([0-9a-fA-F]+)", queryObj["PNPDeviceID"].ToString()));
                    Console.WriteLine("PID = " + regex("PID_([0-9a-fA-F]+)", queryObj["PNPDeviceID"].ToString()));
                }
            }
            Console.WriteLine("Done");
            int c = Console.Read();
        }
    }
}

From there, it looks like it searches an online database for more info. See: getBoardWithMatchingVidPidFromCloud() function.