Plan twice, implement once. Have ready ready backlog for you and your team to draw from every sprint, followed by a second pre-work validation process. When you grab your next card from the queue also pick the one you will do after it. Review and confirm the problem to be solved and the measure of success for that card, the one you will do next, make sure it’s clear and you get it, then post it for validation for the team to review and confirm. That validation happens in parallel to completing the current card, once the current card is done grab that newly validated card, which you can now be confident that the work matters, it’s clear, and there is no confusion. Plan twice; once to make sure that you have at least 2 sprints of ready ready backlog, and then once again, just in time, before the card is started. If you are moving as fast as you should be things should have changed since that card was placed into the backlog 2 weeks or more ago. A second review is well worth it and from my experience no time is lost, only gains are made.