In the latest version of the Android SDK, running "SDK Manager.exe" and/or "AVD Manager.exe" will not open anymore. Even the "Launch Standalone SDK Manager" link in Android Studio, which can be previously found in Android SDK Settings, is now gone.
It is now recommended to perform manual SDK and AVD management inside Android Studio. But for those who do not have an Android Studio or for those who do not like to open Android Studio just to perform SDK management, you can still manage the SDK using the command line tools, "tools/bin/sdkmanager.bat" and "tools/bin/avdmanager.bat".
This information is available when running "tools/android.bat". I think this is true for those who currently have Android SDK tooks v25.3.1 and above.