Accountability without becoming a jerk
Accountability isn't tone. It's clarity about what was expected and what actually happened.
Expectations have to be written
Verbal expectations are remembered differently by every person in the room. Written ones aren't. This isn't bureaucracy, it's how you have the same conversation twice without it being a fight.
Separate the gap from the person
'The standard is X, this came in at Y' is a fact. 'You don't care' is a character attack. The first one changes behavior. The second one ends relationships.
Close the loop or it doesn't count
If nothing happens after a missed expectation, you just told the whole team that the expectation was optional.
Take your version of this question further
This is one operator-tested angle on the question. Your shop, your size, your trade, and your team change the answer. Ask your specific version inside Ask a Shop Owner to get a response grounded in how owners like you actually handled it.