It was a pretty wimpy F1 tornado. You could tell it wasn't going to cause significant damage.
How,pray tell,do you know how much damage it is going to cause?
Under the conditions you described, you may have seen a gustnado, which forms differently and is much weaker than a traditional tornado. They form from horizontal sheer and turn downward, kicking up dust and causing very minor damage. They also typically form at the front edge of a storm, where rising hot air interfaces with descending cold air, which provides the necessary spin.