Basically all briefs can be boiled down into achieving two goals:
business goal and comms goal.
On the business goal side it's about one of three ( or a mix of the three):
- get new customers
- retain current customers
- get more out of current customers
On the comms goal side it's about one of two:
- create a "I knew there was a reason I liked his product/company/etc" reaction
- create a "I never thought of it that way, that's interesting"reaction
Of course multiple business goals are mixed with the two comms goals. Like getting more out of current customers could need a "I never tought of it like that"reaction, etc..
The supporting evidence to help your agency along is:
- new feature
- new product
- old product
- old feature
- mental position in relation to current culture
So there you have it.. the lazy person's guide to briefing.