How to show method parameter tooltip in C#?

Ctrl + K, Ctrl + P

Worked for me where Ctrl + Shift + Space didn't. Perhaps due to Resharper?

Ctrl+Shift+Space will do what you want.

You might want to check out a poster of key bindings.

It's Ctrl-K Ctrl-I for VS2015. In case people from the future are wondering wandering.

I don't understand what you mean exactly. But I use this coding for method parameters tooltip.

/// <summary>
/// Do work function
/// </summary>
/// <param name="id">This is user's Id.</param>
/// <param name="name">This is user's Name.</param>
/// <param name="surname">This is user's surname. </param>
private void DoWork(int id, string name, string surname)
{ 
    // do stuff
}