Why are acceptance criteria written?

Acceptance criteria are written to define clear, measurable, and verifiable conditions that the developed product or its feature must meet to be considered ready and acceptable for the user or customer.

Goals of writing acceptance criteria:

• Ensuring common understanding: Eliminates ambiguity of requirements among the development team, testers, product managers, and the customer.
• Guidance for development: Defines what exactly needs to be implemented for the feature to be considered complete.
• Basis for testing: Serves as a direct source for writing test cases and defining testing scenarios.
• Clear definition of "Done": Allows unambiguous determination of when a task is considered finished and ready for delivery.
• Managing expectations: Helps the customer or user understand what they will receive within the implemented feature.
• Reducing risks: Minimizes the likelihood of incorrect functionality implementation or misunderstandings of requirements.

Acceptance criteria are formulated as specific, verifiable statements, often in the form of a "user story" or a simple list of points.