Rhinos are still without a win following their dreary 10-4 home loss to Catalans Dragons in round three.
They began the season with a strong performance in a two-point defeat by Warrington Wolves, despite having James Bentley sent-off in the opening quarter and Brad Dwyer sin-binned later in the first half.
But they fell away after taking an early lead in round two at Wigan Warriors and never got a grip of Thursday’s game, having again opened the scoring.
Leeds defended well for long spells against the 2021 league leaders, conceding only two tries, but Agar admitted their attack was “painful to watch”.
The coach described the encounter as a “real stop-start” affair, with no flow or tempo.
He said: “We said to our guys at half-time, the first team that really goes after this game and gets some tempo and some momentum will bring it home, but I don’t think it ever got that, from start to finish.
“One of the reasons we didn’t win was because we bombed a load of chances.
“There were a lot of chances and a lot of space we never got to and never executed.
“For me, after last week I thought our effort was up there and they committed to be really good in some areas.
“I thought our kick-chase was really good, they got numbers in the tackle and controlled it fairly well, but our ability to execute was so far off the mark.”
Agar put that down to “some bits of skills being off and some poor decisions with the football.”
He is keen to see Rhinos play an exciting brand of rugby and conceded they are struggling to do that in the early stages of the campaign.
“One thing we have been keen to impress on the players is Leeds’ DNA, playing the style that has been synonymous with the club,” Agar stated.
“I felt [on Thursday] we came away saying ‘we have got to work really hard on this’.
“I felt we sat back too much and didn’t create enough push and support.
“There were times with the ball when it was really painful to watch.
“That is something we have got to work hard on.”
Agar said combinations also need more work.
He added: “We’ve got two new halves and a new full-back in there.
“I know he [Jack Walker] has been at the club a while, but he has not played full-back for us for two years.
“Richie [Myler] has been such a pivotal player in our good ball attack, we just need to make some little adaptations there, getting back to playing with a bit more speed and a bit more push and support.
“When we look at the tape we will see many times when we’ve taken the wrong option and not played when we should have done, which is really against everything we want to be.”
The game was delayed for around 10 minutes in its opening moments following an injury to Alex Mellor, who was taken to hospital after being carried from the field on a stretcher.
The club confirmed he was later allowed home and has been “cleared of serious injury”. He will be ruled out of next Thursday’s derby at Wakefield Trinity, but Rhyse Martin could be available following compassionate leave and Harry Newman (hamstring) is also expected to play.