Jafar calls the Sultan an "addlepated twit," and we can't really disagree. After all, the ruler of Agrabah plays with toys, unknowingly confides in the villain, and spends the majority of his time trying to get his daughter to marry whatever random prince waltzes through the gates of the palace.
He's not the brightest bulb in the bunch.
Overall, the Sultan is portrayed as pretty childish—but also well-meaning. Sure, he plays with toys, but he's also trying to run a kingdom on the side. He's soft-spoken and gentle, and he doesn't like to ruffle feathers. Except Iago's.
Of course, that means it's comically easy for Jafar to manipulate thus guy. And, heck, if regular old manipulation doesn't work, Jafar's always got his hypotonic snake staff handy. Ever notice that you don't see Jafar using that snake staff on Jasmine or Aladdin? Maybe it only works on weak minds? The Sultan is a prime candidate right there.
But the crazy thing is the Sultan actually thinks he can rely on Jafar. He calls him, "my most trusted advisor." That's supposed to be a big red flag right there. The Sultan's judgment is not the best.
Naturally, of course, the Sultan thinks he's "an excellent judge of character." We're gonna have to quote Iago here—"Not!"
As far as being a good dad goes, we're gonna give the Sultan a pretty mixed review. Sure, he loves his daughter Jasmine and legit cares about her happiness, but he does keep pushing her to just stop complaining and marry a prince already. Literally. Any prince will do:
SULTAN: Dearest, you've got to stop rejecting every suitor that comes to call. The law says you...
BOTH: ...must be married to a prince.
SULTAN: By your next birthday.
JASMINE: The law is wrong.
SULTAN: You've only got three more days!
JASMINE: Father, I hate being forced into this. If I do marry, I want it to be for love.
SULTAN: Jasmine, it's not only this law. I'm not going to be around forever, and I just want to make sure you're taken care of, provided for.
See? He's a real mixed bag. On one hand, the Sultan would really like for Jasmine to just pick a prince to marry already so they can stop squabbling all the time. Even if that prince is a pompous jerk. On the other hand, he loves his daughter and really hates to force her into something she doesn't want, even if he thinks getting a big strong man to take care of her might secretly be good for her in the long run.
What can we say? The Sultan's a bonehead with a heart of gold.
In the end, the Sultan finally redeems himself when he wakes up and realizes that he's the ruler of Agrabah and he can change these laws if he wants to:
SULTAN: You've certainly proven your worth as far as I'm concerned. It's that law that's the problem.
SULTAN: Well, am I sultan or am I sultan? From this day forth, the princess shall marry whomever she deems worthy.
Oh, so this has been a thing all along? It's a real deus ex sultan. Aside from the fact that this is super convenient, no one minds. The Sultan saves the day, and everyone is happy. High fives all around. You did it, Sultan.
Now can we talk about changing the penalty for stealing apples in Agrabah? It seems a little over the top to us. Hey, we're just saying.