Let us assume we have our prototypical European dragon representative over here, George. He has four ground-limbs with four clawed digits including an opposable digit on the forelimbs, normally is quadrupedal when walking around, and has forelimbs somewhat longer than the hind limbs, in addition to the traditional scales and toasty-breath. The big fellow has a big brain to match, too -- easily on par with an intelligent human.
However, how would he write anything down? Dragon limbs and digits are big and chunky with serious pointy ends, designed for walking, pushing off for takeoff, and assisting with feeding -- despite having grasping capabilities, they certainly are not designed for fine motor skills.
You can come up with any sort of instrument you wish to assist the dragon in his goals, but modifying the dragon for improved fine motor skills is out of the question.
Furthermore, what sort of script/writing system would lend itself to being used by such a large and clumsy creature? Would they be stuck with large-print on their clay tablets? Or would a different type of writing system be better for the application?