Just finished MOI Prologue and... is Tool stupid?

Just finished with the same, and the one thing that is bugging me the most (apart from the identity of the beast and the sudden compassion shown by Krull) is the sheer idiocy of Tool in freeing Raest.

From what the prologue 1 hinted at, a Jaghut Tyrant is a far bigger deal than what we understood it to be in the first book. In power scale, he (Raest with his Finnest) might be a weaker character than Icarium the Jhag, but wayyy stronger than Anomander Rake, I think. From Deadhouse Gates we can see what an Azath House actually is, and the Tremorlar was a house that pinned entire Raraku. That is how powerful the Finnest must have been for an Azath to suddenly spawn. So, strength-wise, Finnest of Raest = Raraku??

Now, the entire reason the Tlan Imass went and became immortals (which is a very cursed thing apparently) is to kill Jhaghut, and the Tyrants are supposed to be like the peak of that. Given how they all decided to collab to chain Raest, we can see how powerful the guy is.

Then I dont understand how anyone, anyone can convince Tool, one of the strongest Tlan Imass (maybe the Unwelcome is stronger at the end of Book 2?) to go free the Raest. Especially when I dont think Tool has any idea whether Anomander Rake is strong enough to handle him or not.

Then again, Anomander Rake didnt bother himself with Raest at all (ofcourse, Raest without his Finnest)

Basically, this prologue, along with the entirety of Book 2, is suddenly making me question Book 1. When reading Book 1, I did not understand how powerful any of these people were, and I was like Anomander Rake, is it. But now, I feel like Rake was a step away from dying.