From Sharath's book Astanga Yoga Anusthana.
Satya means being truthful to others both in words and and actions, not telling lies, and following a path that is true and honest.
Speak the truth that is sweet, do not speak the truth that is not sweet. Do not lie to please. This is the eternal dharma
satyapratisthayam kriyaphalasrayatvam ys 2.36
By being truthful whatever action you take will be successful.