This isn't just internal. Research at Google has an app in the play store called AI Test Kitchen. I've used it, and it's... not great. The format is for specific things, like describing a place you say or giving you a list of tasks to reach a stated goal. The descriptor type is decent, but the task list is awful. It frequently includes the goal as a subtask, much like "draw the rest of the fucking owl." It's interesting but based on what I've seen it's not there, nor close. Could be they don't want to publicly tip their hand yet, since this is a public (wait-listed) version. Time will tell.