Andy Farrell admits Ireland's laboured win over Georgia was unacceptable and accused his players of lacking belief.
The Irish failed to assert their dominance over inferior opposition in Dublin as they ran out unconvincing 23-10 victors to secure second spot in Group A of the Autumn Nations Cup.
Tries from Billy Burns and Hugo Keenan helped put the hosts 20-7 in front at the break but they were unable to add to that advantage during a dismal second half, which finished 3-3.
Asked to assess the performance, head coach Farrell said: "Not good enough, not good enough. Certainly in that second 40, it wasn't the standard we expect of ourselves, especially playing at home.
"After a first 40 that was decent enough, flowing at times, still obviously things to fix at half-time.
"In the second half, I just thought we didn't have any courage of our own conviction.
"Georgia thoroughly deserved to earn the right to slow our game down by being total menaces at the breakdown, and all credit to them for that.
"But that's not good enough from us."
Victory for Ireland ensures they will host Scotland in next weekend's third-place play-off.
However, the manner in which it was achieved is a far more pressing matter for Farrell, who had made nine changes to the team convincingly beaten by England last weekend.
Georgia had not registered a point in the competition before arriving at the Aviva Stadium but broke their duck in fine style with a superb solo score from Giorgi Kveseladze.
While he offered a frank assessment of the overall display, Farrell also questioned the decisions of referee Mathieu Raynal to not allow first-half tries for Stuart McCloskey and James Ryan.