Formulating research interests — context/motivation or not?
Don't even use bullets; just provide a list of keywords/phrases identifying your subfield.  At least in the US, departments ask for a separate research statement in addition to your CV.  That's the place to explain your research interests in detail and give them context; there's no need to do that in your CV, too.

For example, when I applied for faculty positions, my CV included the following lines between my contact information and my education history.


  Research Interests
  
  Algorithms, data structures, and lower bounds; computational and discrete geometry; computer graphics


I've served on the faculty recruiting committee in my (top-10 US computer science) department for several years; this approach seems both standard and effective.  Personally, when I read a CV, I only spend a second or two on the self-declared research interests and jump straight to the publication list.

(Posdef's answer suggests giving more context in your cover letter, but I think this is pointless.  I don't know anyone who has ever read a cover letter.)