What are acceptance criteria?
Acceptance criteria are a list of expectations that a user will have, when using a feature. They are written in short sentences to define a specific behavior of a feature, and they are commonly added to user stories to add more description.
Do you have any examples?
Examples could be, the widget should have a text box and character count. Entering characters to reduce the character count could be another example. Or the third one is when character count is at zero, no more characters can be added to the text box.
What's the value?
It gives the team a boundary on what they should and shouldn't be delivering in a feature, and acceptance criteria, can help with discussion and collaboration of features. And acceptance criteria can help testers generate test ideas and identify risks.
Are there any pitfalls?
Acceptance criteria can help stem testing ideas, but they are not tests themselves. And vague acceptance criteria can potentially lead to misunderstandings, and bugs in the system too.