If no serial is passed, then the command would work if there is exactly
one device connected, but will fail with multiple devices.
To avoid such cases, ensure that a serial is always provided.
On Windows, adb is provided in the release archive. Most missing adb
issues come from users setting the ADB environment variable to an
incorrect value (on all platforms).
Suggesting to install platform-tools to solve the problem will just make
things worse (there will be one more adb in yet another location).