Why not 了 at the end? This is a decision that I made (completed), so why not 他认为我做了的决定很好？
What is the difference between 我做的决定 and 我的决定？
The difference of "the decision I made" and "my decision".
Ah, as they say, "same difference", then.
Do you think this is better? Or is this similar? "他认为我做的决定是很好的“