From the two episodes I watched, those descriptions are infinitely more exciting than the show.

Yeah, the show tends to lean on Mr. and Mrs. Smith's lives more than their jobs so it does kind of misrepresent itself. But not as much as those descriptions! In fact, it feels more like the original show that inspired the movie.

To me it felt like the actors were given the outlines of each scene and then improvised the dialogue, and the direction was very "flat". The missions didn't make sense to me. The package in the first one seemed likely to be going to the same destination, so why intercept? In the second, if John Turturro was the target, why not just tell them? Or was it literally whoever bid highest? Exactly what information was being sought, or was it just whatever the target happened to reveal? The Alexander Skarsgard/Eiza Gonzalez pairing in the prologue might have made for a more entertaining show.

Yes, the missions seem very confusing (the woman was expecting that cake?), but subsequent episodes lead me to believe they may be in a probationary phase of their employment. It seems like they're being tested. They got one strike for Turturro and have to level up or be terminated (or worse, terminated!)

You could be right, but we're probably going to drop the show as there's so much that we positively enjoy to catch up on rather than carry on with something in the hope it will get better.