According to the Genesis account, Satan never lied to mankind. Their eyes opened just like he said it would. And they did not die in the very day of eating it - just like satan said they would not - contrary to God's claim that they would. Also, because of eating of the fruit, man has the opportunity to go to heaven and live like a god with God, forever! Would man have had that glorious opportunity had Adam and Eve not eaten of the fruit? So Satan's claims turn out to be spot on! It is God's claim that they will die in the very day of eating the fruit, that turned out to be a lie.
I don't believe the writer of Genesis 3 was attempting to portray Satan as a liar. In fact I don't believe the writer of Genesis 3 was even knew about Satan! The first 3 chapters is obviously an ancient creation myth in the tradition of "Just So" fables designed to provide answers to such questions as:
Where did the world and all humans and animals come from?
Why are people ashamed to be naked?
Why do women have painful childbirth?
Why do men have one shorter rib than women?
Why do men dominate women?
Why do we have to work so hard to live?
Why do we die?
Why do serpents not have legs?
The chapters were later coopted and reinterpreted as having deeper symbolic meaning and that's how the serpent came to regarded as being satan or satan's puppet. There is nothing in the text itself to indicate the snake is being manipulated by satan, In fact, the text itself explains the serpent's conversation with Eve by saying that serpents are by nature very wise/crafty. So not only does the writer not give any indication of the snake being manipulated by a higher power, he also give the impression that the snake is acting that way because of its own inherent nature!