How does Tireless work in terms of last card, boosting and drawing itself?

Question

Accepted Answer

Tireless must be the only card in your hand when you play it as an action. It draws a new hand immediately, so in a solo game you can boost it with those cards; boosting it with your last cards instead means its effect does not trigger. If a reshuffle is needed, Tireless itself can be drawn.

Kinfire Delve: Vainglory's Grotto

How does Tireless work in terms of last card, boosting and drawing itself?