Through my experience as the owner of a recruitment business, corporate management and ownership of various trading companies, as a business consultant and executive coach I KNOW I haven't always 'got the brief right first time'. Even when I was hiring for my own companies, it was easy to 'fill a chair', to be so busy as not to put the right time into the strategic thinking as well as the operational thinking about, 'what worked and what didn't work' about the last person, the last job description!
Things got so much better when I got better at ether giving or receiving the brief - exercised caution about assuming the 'cutting list' (person and job description) was right for today AND tomorrow.
Then I always look to offer up two individuals who fit the agreed JD and PD and at least one of whatI call 'the wild card'! Someone who doesn't so much fit the prescription but who brings the right dynamics, EI and opportunity. Obviously there may be some pre-requisits but they are often not as definite as they first may seem!