Use Newton's Method to compute sqrt(x)
The sqrt-prime function neither needs nor uses the last-guess argument.  It can be safely eliminated:

(define (sqrt-prime guess x)
  (if (good-enough? guess x) guess
      (sqrt-prime (better-guess guess x) x)))


You may call the function thus:

(define (sqrt x) (sqrt-prime 1.0 x))


I feel that, other than this minor change, your program is succinct enough.