The former Real Madrid defender and Malaga midfielder say they are armed to battle for the league championship this season.
Carvalho, 35, and Toulalan, 29, were unveiled for the newly-promoted Ligue 1 outfit on Monday and have already made their intentions clear about what targets they expect to achieve at the Principality-based club.
"We are armed to fight against Paris Saint-Germain, but there are other teams as well," Toulalan told reporters.
"The goal is to be the champions."
Monaco has spent over 130 million euros on new signings such as midfielder Joao Moutinho and Colombia strikers James Rodriguez and Radamel Falcao. Eric Abidal also signed a one-year deal on Monday.
Former Real Madrid defender Carvalho knows there is competition for places but he is determined to prove he is still good enough to play despite entering his twilight years.
"I feel good, I will fight to win my place in the team," he said. "I know Falcao well and he is a very dangerous striker who has added real value to our club. I had other proposals but I felt Monaco was the best. The important thing is I believed in this project. We will grow step by step.
"I played in the Portuguese League, English and Spanish, I wanted to discover the French Championship and I was very well received by the group. I'm very happy for Abidal, we know the quality he will bring us."