The scores from the other tests are used to determine what type of specialty you might be best suited for. These "composite" scores (also known as line scores, MOS scores, or aptitude area scores) are calculated by adding together combinations of the different sub test standard scores. These composite scores are then used to determine which different military jobs (aka Military Occupational Specialties or MOS) may be the best fit for you. Each branch of the military will have their own approach to these composite scores.
The various armed forces adopted all of those aspects in 1976. At that point in time, the test was in its written form rather than today’s more common form (computerized test format). The written form covers all of the previously mentioned areas as well, which is why both forms are still available. All-in-all that answers the question concerning the intention of the test.