By Alvin Alexander. Last updated: December 26, 2017
I don’t know much about LibGDX yet, but one thing I’ve learned is that if you get the LibGDX error message, “Your Android SDK path doesn’t contain an SDK,” it’s because the LibGDX setup tool doesn’t work automatically with the Android SDK tools that you download from the Android website, at least not the default tools. (That directory may work after you do some configuration with the sdkmanager, dunno.)
As I’ve learned, the correct directory on MacOS is /Users/<username>/Library/Android/sdk. I haven’t looked into it, but I assume that directory is created by Android Studio, and I can confirm that as of December, 2017, the LibGDX project setup tool will work if you give it that directory.