Apart from a host of poor second half wides, Laois spurned three gilt-edged goal opportunities in the opening period.
Brendan Quigley had a shot brilliantly saved by Philip McEvoy, Padraig Clancy blazed over with Colm Kelly completely isolated inside him and Billy Sheehan fisted over from straight in front of the posts with only McEvoy to beat.
McNulty warned that his men would need to develop much more of a killer instinct if they are to contend come the summer.
“It was a good start, a positive way to get the year in motion,” said McNulty.
“We need to recognise that there are major areas for improvement in terms of performance and recognise it’s going to be so much tougher next week.
“I’d say you would have to be happy with 20 points. The conditions were perfect for scoring points but I would question why we didn’t actually score more. Armagh missed chances which could have made the game tighter for us when we should have had the game totally in control.
“We had a few goal chances. It’s something I talked about. When you get an opportunity to go for goal you go for the jugular, and we didn’t execute that as well as I would have liked.
“We took our foot off the pedal certainly. Armagh totally dominated midfield and won the vast majority of our kickouts. It’s something we have to look at on the videotape… it is not acceptable. Against different opposition we might be punished more acutely for that.
“There are positives and you have to be happy with those positives but if you’re happy that that’s as good as you can get then you’re in trouble. I think there are so many areas for improvement in our performance and we’ve got to get working on those improvements if we’re going to be seriously competitive this year which is what we want and we’re seeking to do.”
Most of the positives came in the first half, when Laois played with a fluidity that a very inexperienced Armagh side couldn’t live with.
Paul Grimley made a change at midfield just before the interval though, with Stephen Harold coming on for James Lavery, and that led to a huge turnaround after the resumption, when a 10-point deficit was reduced to three.
Laois weathered the storm though to secure the honours.
The eye-catching Ethan Rafferty got Armagh off to a flying start with a brilliant point after just 25 seconds and the visitors were two clear after six minutes.
Laois took control at that juncture though, with Ross Munnelly and the returning Donie Kingston scoring seven points between them as the home side led by 0-13 to 0-4 at half time.
Another Munnelly point stretched the gap to ten but with Armagh holding sway in the middle third, they began to chip away at that margin. Brian Mallon, Mark Shields, Harold and Rafferty all chipped away with points and when Mallon goaled in the 47th minute, the margin was suddenly down to three.
They couldn’t get any closer though and a late flurry of scores, including a brace from Sheehan, gave Laois some welcome breathing space in the closing minutes.
Scorers for Laois: R Munnelly 0-7 (4fs), D Kingston (1f), B Sheehan 0-4 each, D Strong, 0-2, P Clancy, C Boyle, B Quigley 0-1 each.
Scorers for Armagh: B Mallon 1-1, S Forker (2fs), E Rafferty 0-3 each, G McParland, S Harold, M Shields 0-1 each.
LAOIS: E Culliton; C Healy, K Meaney, P O’Leary; D Strong, J O’Loughlin, C Boyle; B Quigley, C Begley; R Munnelly, G Walsh, B Sheehan; D Kingston, P Clancy, C Kelly.
Sub: D O’Connor for Kelly (47); A Doran for Walsh (58).
ARMAGH: P McEvoy; M Shields, J Donnelly, G McCooey; K Dyas, C McKeever, F Moriarty; J Lavery, K Toner; C Rafferty, A Forker, E Rafferty; G McParland, S Forker, B Mallon.
Subs: S Harold for Lavery (30), A Duffy for A Forker (51), E McVerry for Mallon (59), J Kingham for McParland (60), S Campbell for S Forker (70).
Referee: R Hickey (Clare).