If any one saith,that,by the Catholic doctrine touching Justification, by this holy Synod inset forth in this present decree, the glory of God, or the merits of our Lord Jesus Christ are in any way derogated from, and not rather that the truth of our faith, and the glory in fine of God and of Jesus Christ are rendered (more) illustrious; let him be anathema. [Council of Trent, Canon 33 on Justification]
There really isn't anything to observe here with respect to our present focus on whether Trent teaches justification by grace alone. So instead, by way of concluding summary, I hope that is sufficiently clear now that Trent in no way teaches a “works-based” gospel, and their detractors really need to cherry-pick in the most abominable way in order to pretend otherwise. The great chapter VII of the Decree on Justification (discussed here) leaves no room for any doubt about the subject, declaring as it does what exactly the causes of justification are. It ought to go without saying that none of them are human; all the causes of our justification are found in God, his grace, his purposes, and his glory. None of them are found in us.
Now if this is what Trent explicitly teaches, it is gross falsehood (hopefully born in ignorance, but falsehood nonetheless) for anyone to say that the Catholic Church teaches a justification based upon human works.
But maybe some will say that Vatican II has changed the game in some way, and that this later council has taught justification by works. So we will be turning our attention to Vatican II, and later to the Catechism, to see whether our critics can sustain their complaints there. Clearly they cannot sustain them from the teaching and canons of Trent, nor of St. Thomas, as we have seen.