The team has debuted a significant package of bodywork and suspension changes that were supposed to have run for the first time at the cancelled Imola event last weekend.
Despite the obvious complications inherent in learning about a new package on a tricky street track, the team opted to keep them on the car and put some miles on them.
Lewis Hamilton finished FP2 in sixth place while his team-mate George Russell was 12th.
"It's difficult with Monaco, really difficult to judge," Wolff told Autosport when asked about the upgrades.
"But at least we haven't seen any behaviour of the car that would have been deemed as really negative."
Asked if the car was giving the drivers the confidence they require, he said: "I've never heard a driver saying in Monaco that feels good!
"I think it's always on the knife's edge. You've seen that with [Carlos] Sainz. And therefore not lots of great praise, but definitely going in the right direction."
Wolff stressed that he was proud of the effort made by the team to get the new parts to the track.
"Massive," he said. "You see the whole bodywork is different, front suspension, the floor is different.
"A mega job of everybody in Brackley to have delivered that, and now this is our new baseline and we have to work from here."
Wolff also noted that after a disappointing FP1 session, Red Bull made progress in the second session, and reckons Max Verstappen showed he is a step ahead of the rest of the field.
Source: Autosport