There's a forum online where restaurant chefs are sharing the "red flags" you should look for that reveal a place is "low quality." Most of them are things you could notice BEFORE you order. Here are a few . . .
1. "Smell. If it's a sour smell or disinfectant smell . . . red flag."
2. "If there's a fish tank, take a look at it. If it's clean, the kitchen is too."
3. "Dirty bathrooms and dirty floors equal dirty kitchen."
4. "A huge menu is a sign that food is frozen and the ingredients aren't fresh."
5. "Carpet is one of the most disgusting things. Vacuuming only goes so far."
6. "The bread. If they can't get the bread right, they don't know anything."
7. "If you can smell the seafood when you walk in, then it's not fresh."
8. "If you see lots of plates left half-full, run."
9. "When you walk in, and you aren't greeted or nobody makes eye contact."
10. "Stock photos on the menu. Cheap silverware as well."