Ah. So Ishtar's requirement to always tell the truth turns what would ordinarily be taken as statements of intent into binding oaths. It might feel like a cheap out, but what if Ishtar just adds the words "I intend to" before saying what she's going to do? Ishtar's allowed to change what she intends to do later right? Or "my current intent is to" if we take it a step further.
As someone who's naturally a bit too literal himself, my curiosity is particularly piqued.