I have to admit that I've been on both sides of the fence. In earlier days, when commissioning adverts and brochures, I have been the one who has been reluctant (lazy) to spend time thinking about what it was that I actually wanted to communicate. It was much easier to get the poor copywriter to compose a piece to say what they thought I was trying to, and then have a discussion with them to explain that their offering was missing some salient points, and could they please try again. To be fair, sometimes they would get it spot on first time - especially the ones who I'd used before, and knew something about the product, and perhaps more importantly, about me!
It's so much easier, isn't it; to look at some text and say that you like this, don't like that, this is going in the right direction, and this is a bit too wide of the mark; and you can't say that - the ASA will be on me like a ton of bricks if this goes out! Marketing Managers and Brand Managers like to have things easy - well, we all do truth be told.
But this is one of those situations that you have to be strong, and fight your corner. After all, this sort of copywrite ping pong (or whiff whaff as Boris Johnson would have it), is being played out at the expense of your time. So you need to educate your client into furnishing you with a brief. Even the briefest of briefs.
Demanding a brief is not only unproductive, it will probably get you taken off the list of outsourced agencies the company prefers to use. So it's not a great idea. What you need to do is point the client in the general direction of what is required, and here are some pointers as to what you might suggest.
Ask your client if he can "establish a positioning statement". Sounds good doesn't it? But it does sound professional, and it will get the Manager thinking along the right lines. All you're trying to do is tie down some bases. Examples of which could be:
"Who is your target audience
"Product or service USP's (unique selling points)
"Would a humorous approach be appropriate
"Brand Image / Identity
"What consumer need is being addressed
As always, research on what the competition are doing / have done, and what your client's advertising history is essential - if you were being asked to follow an advertising trend, you would expect this information to be volunteered, but if it isn't, and your research suggests that this may be the case - ask.
Get into the habit of guiding a reluctant client gently towards the commitment of a brief - better still educate them into providing a clear brief at the outset. Remember - it's your time that you're going to be saving, and it makes for a good working relationship.