A call, or async if you prefer.
I want to know what the project is supposed to do, who it's for, what's working now, what's broken, and what success looks like in 90 days.
For a website, that's traffic, the right audience finding the page, conversion. For a campaign, it's opens, clicks, leads, attendance. For an event, it's the experience on the day. For print, it's whether the piece actually gets read in the environment it'll live in.
I send you a short written brief at the end of this phase, so we both know we understood each other the same way.