have learned an important lesson from my combined experiences at all the places I've worked. That is: raw requirements cause waste. A term I've used (and have heard others use) is that requirements are either "baked" or "not baked". For a development team to plan an iteration, or a scope of delivery, the requirements need to be baked. If we pull the development team into a planning session, we ensure the requirements are fully baked before the meeting. Developers will be asking specific questions about the details of the requirements, and answers need to be readily available.