Only God can not fail. = Good.
Jesus at that moment in time when asked that question was not functioning as God.
He was functioning as a sinless man. A man who could experience being tempted.
He made himself become as Adam before the fall...
Jesus had to become that in order to qualify to die in our place for our sins.
Who, being in very nature God,
did not consider equality with God something to be used to his own advantage;
rather, he made himself nothing
by taking the very nature of a servant,
being made in human likeness.
And being found in appearance as a man,
he humbled himself
by becoming obedient to death—
even death on a cross!
Philippians 2:6-8
Also to be noted...
God can not die.
Only God who cannot die is good.
So, Jesus could not resume being as God until after He finished His work of dying on the Cross!
“Why do you call me good?” Jesus answered.
“No one is good—except God alone."
grace and peace ........