Nowhere in that character brief suggests that Ahsoka was intended to be annoying.
I don't believe that for a second.
Don't get me wrong, I was surprised and happy with the character development over the series for Ahsoka.
But I think it's pretty obvious that they all thought her initial feistiness and attitude would make her seem "strong" and "cool" to fans.
That works when the fanbase is all children... maybe they forgot that there would be a lot of adult fans watching the show as well.
I find writers are doing that a lot more these days. I'm guessing it developed out of the tv/film hero characters from the 80's. A lot of popular heroes (cops, buddy cops, soldiers, etc.) were written as rebels, who go against orders to get the job done or do what's right.
But these days, it seems like a pre-requisite. I was watching WandaVision over the weekend, I couldn't stop thinking the Rambeau character would never have gotten very far in a military/government organization if she's berating her boss in public like that....