Visual COBOL Build Tools for Windows requires the same license as the Visual COBOL IDE products (i.e. Visual COBOL for Visual Studio or Visual COBOL for Eclipse) so you need to ensure that you have enough licenses to cover your use of both Visual COBOL Build Tools for Windows and any other Visual COBOL development product on Windows.
For example, if you have purchased six development licenses and install one instance of Visual COBOL Build Tools for Windows you can install an IDE-based Visual COBOL product or Visual COBOL Build Tools for Windows on a maximum of five other machines.