Circumspect

Circumspect: cautious; wary; unwilling to take risks

It is good to pay very close attention to details.  To be circumspect, however is to take it to a fault.  The circumspect person is afraid to make mistakes. 

Meticulous is a closely related word.  A meticulous person is fussy over details.  They want everything just right.  Interestingly, meticulous derives from the Latin word metus, which means fear.

Both circumspect and meticulous describe someone who is nervous when it is time to take risks.

Circumspect derives from Latin circus, circum (ring, circle, around, about) and spectare (to see, to look at carefully, to watch).