Weirdly enough, the tooltip documentation on my Visual Studio 2015 Community Edition when using Xamarin 6.1.1 (and I think the previous version as well) doesn't appear correctly. They all written as "To be added", even on the common C# method like int.TryParse().
If I'm working different project other than Xamarin (such as a console app project), there's even no "To be added" tooltip. Just blank.
I reckon there's such tooltip help, that for example, explaining briefly of the method usage. I don't know why it's gone, maybe accidentally pressed something.
Is there any way to show it / maybe I need to download it first?

