"Sure, let's add some acceptance criteria to this ticket, so Vernon knows how to test it."
With genuine love and respect, no, No, NO, NO!!! Now I can hear you saying, "Whoa Vern! Why the allergic reaction brother?". Acceptance criteria aren't just about testing! If you're not a tester and think that's the case, this post is for you!
Allow me to explain!
Here are 5 specific reasons why that bothers me:
Vernon != Testing. This isn't about one person or a single activity. This is about enabling all roles and activities on the team!
It clarifies what we're delivering. How do we know when to stop building without capturing acceptance criteria as a team?
It enables us to commit. Can we deliver the work if we haven't agreed on what we're building?
"Make X the same as Y" is a trap! There is always, and I mean ALWAYS, hidden information, caveats and undocumented behaviour in that system we're replacing. So let's make it visible now before we get blindsided!
Makes us resilient to lottery wins! If we aren't capturing team discussions, what happens when the person with the know-how hits the jackpot and heads for the beach?
So the next time your testing teammates insist there are acceptance criteria on the story, don't be fooled!
This is about the whole team, not just the tester!