Final answer:
Calipers are the most accurate tool for measuring body fat directly through a skin-fold test, while measuring tape is used to assess visceral fat through waist circumference.
Step-by-step explanation:
The tool that measures body fat most accurately is the caliper. A health professional uses a caliper to conduct a skin-fold test where the thickness of skin is measured at various parts of the body to assess body fatness. This method is noninvasive and fairly accurate, though it is often compared to standards that are most representative of young to middle-aged adults. On the other hand, for measuring visceral fat, which is a key predictor of disease risk, a simple measuring tape is used to gauge waist circumference. Both men and women have specific waist circumference thresholds that indicate higher health risks if exceeded.