In this context, the term toned implies leanness in the body (low levels of body fat), noticeable muscle definition and shape, but not significant muscle size ("bulk").
Research and basic anatomical knowledge imply that the notion of specific exercises to improve tone is unfounded.
Exercises can aid fat loss or stimulate muscle hypertrophy, but cannot otherwise improve tone.
More accurate descriptions are "muscle building" and "fat loss."
Exercises popularly believed to improve tone are primarily weight lifting exercises performed with high repetitions and low resistance (low weight), with short rest periods.