Words alone are not an act of perfect contrition no matter how beautifully arranged.
It is the sincerity and resolve of the penitent that makes it perfect.
Perfect contrition could be as short as "I'm sorry" for someone properly disposed.
The act of contrition rattled off in confession without sincerity and resolve would hardly qualify for an imperfect act of contrition.
Right. I've never understood that there could be some formula for a perfect act of contrition, like a certain prayer entitled "Perfect Act of Contrition". Perhaps it could articulate the dispositions required, but simply reciting the prayer does not equal a perfect act of contrition. I vaguely recall some prayer books where there's a prayer called "Perfect Act of Contrition" that could be misleading.
As for the imperfect, that's where God's mercy most manifests itself. Generally, unless a penitent demonstrates otherwise, the fact that they approach the Sacrament generally indicates at least an imperfect act. Contrary examples might be, "My parents are making me go but I'm not really sorry." Or someone who comes in seeking counseling and wanting to vent (common in the Novus Ordo). But if you're there and sincerely confess your sins and are at least motivated by not wanting to go to hell or wanting to return to the Sacraments, combined with the intention of ceasing from committing the sin, God's mercy supplies the rest.
Finally, one thing that is OFTEN forgotten ... though it is mentioned above. Trent does not teach that an act of perfect contrition by itself can justify. There must also be the intention/resolve to go to Confession ("in due time"). That last qualifier basically means that you don't need to immediately go to wake up a priest at 3AM to go to Confession, but can go at the next opportunity. But perfect contrition cannot justify a soul who had fallen from the state of grace without the explicit intention/resolve to go to Confession. It basically means that it's non your calendar and you're committed to going, and not just "I'd like to go to Confession, but I'm too embarrassed." But it's a typical omission you often hear, and especially among the Conciliars many believe they can make some in-their-view-"perfect" act of contrition and then return to the Sacraments without any intention to go to Confession.