Auto-Create Annotation without Overlap

[MatsHardy]

My client has file geodatabase that store the slope data. The geodatabase have 3 feature class, one slope polygon feature class, one slope annotation class and one annotation border ploygon feature class.

Now my client wants to import slope polygon and he wants to create the annotation automatically so that the new annotation will not overlap with the old one. How can I do so in ArcMap?