Career
Aside from the name and relationship to the rulers, the sources do not have any information about the person. The sources are Diodorus 17.5.5 and Plutarch Artax. 1.1.5. The latter explicitly names Ctesias (the physician of Artaxerxes (II) Mnemon) as his source.
Ctesias, however, names Artostes as the son of Darius II, and Ferdinand Justi suggests that the sources confused Artostes as Ostanes.