What is a Definition of Ready?
The definition of ready is the team's checklist for backlog items entering a sprint: clear enough, small enough, acceptance criteria present, dependencies known. Its mirror, the definition of done, gates work leaving the sprint. Ready guards the entrance; done guards the exit.
Use with a light hand: a rigid DoR becomes a mini-waterfall stage gate inside agile. It's a conversation-forcing tool, not a bureaucratic bouncer.
Worked example
A story arrives at planning: "improve search." Against the DoR — no acceptance criteria, unsized, and "improve" undefined — the team declines it and refinement takes it back: "search returns results under 200ms for the 1,000 most-common queries; typo-tolerance on product names." Next sprint it enters cleanly, and the sprint doesn't spend day three discovering what the story meant.