When you create darts, the dart pivot / apex point will sit directly on the apex, such as a bust apex. This is fine for drafting and manipulating the patterns, but it should be moved before output.
For a more flattering look on bust darts, the dart pivot / apex point will be dropped 3/4" / 19mm to 1" / 25mm away from the model's apex point.
The Adjust Dart Apex tool does that quickly and accurately for you.
Select the dart apex you want to adjust from the drop-down list.
Enter a value to move the apex. A positive number will raise the apex and a negative one will drop it.
This is the result of a drop. Notice that this was dropped a very large amount so you can see the process.