France warm-up a Rugby World Cup 'dress rehearsal' for McDermott's Australia
The Wallabies face the host nation and one of the pre-tournament favourites at the Stade de France in Paris on Sunday.
Australia start their World Cup campaign against Georgia in the same venue on September 9.
"It's a dress rehearsal," McDermott told reporters. "What a perfect opportunity for this group to test ourselves against one of the best teams in the world.
"A team like France, you come up against them, that's World Cup intensity and we're going to have to be up from the start of the whistle to be ready to go," he added.
On Friday, three-time winners New Zealand suffered a record 35-7 loss to World Cup holders South Africa at Twickenham in their final warmup match.
The defeat came exactly two weeks before the All Blacks play France in the competition's opener.
"The group chat was going off because we couldn't believe what was happening," McDermott said.
"The All Blacks clearly got beaten up front and that's a lesson for us to take into this game tomorrow.
"France have New Zealand first up, so they can't afford to come out of the blocks slow and we're not expecting them to either.
"We know we're going to cop a couple of punches early, we've got to make sure we continue to punch them back," the 24-year-old added.
Former All Blacks head coach Steve Hansen, who led his former side to the World Cup trophy in 2015, has been with the Wallabies squad this week as an unpaid consultant.
"He was very quiet this morning," McDermott joked, hours after the heavy Springboks defeat.
"He's very experienced in the World Cup arena and that's where we've picked his brain," he added.
La Rochelle's 145kg lock Will Skelton will lead Australia for the first time this weekend against four of his club team-mates.
Skelton, 31, was selected as skipper for the World Cup ahead of experienced flanker Michael Hooper, whom head coach Eddie Jones omitted from the squad in a huge surprise.
"He's a special leader," McDermott said of Skelton.
"Because he doesn't speak as much as your traditional leaders, when he speaks he has the whole room at the drop of the hat.
"I can't wait for tomorrow to support him," he added.