If you really don't have much project experience, how to list your project descriptions when applying for a Ph.D. position? I am applying for one Ph.D. program of computer science(CS). I was required to handle the list of my project description which is up to three pages. However, I am only a fresh graduate student who has moved to the field for only less than two years. I was in the field of electronic engineering(EE). I can only recall three relatively large projects and several small course projects relevant to CS. 
Should list those course projects? I just made some toy examples in those projects.
Should I explain my large projects as detailed as possible so I can stretch out my description to three pages? I saw, on the resume, people usually only use one or two sentences to describe what they did in a project.
Should I list my projects of EE? They are basically non-relevant to my current field but can prove my coding ability.
I am in STEM but not CS, so this is general advice from my experience with graduate admissions in physics + chemistry. Disclaimer that this can vary for different institutions and different application reviews. An application review committee will often want to see: 


Have you demonstrated success at the skills required for successful conduct of research in the graduate program? 
Have you demonstrated mastery of the necessary undergraduate content? 


Based on my STEM background, I would offer the following advice:

Thoroughly explain your background, but don't make it longer than necessary. They read many applications, don't make it longer just for the sake of being longer. It's obvious when this happens, and it reflects poorly on the application. 

Emphasize the skills you've acquired and applied. You might consider briefly explaining the purpose/goals of the project, and then even have a separate section about the skills acquired/implemented in the project that would be most transferrable to your graduate student career. 

List everything you've done. I shot myself in the foot assuming that every undergrad did the things I did, and not stating them explicitly. Perhaps your course project descriptions will be briefer, and perhaps the committee won't care, but it's unlikely it would negatively affect your application in comparison to not including them at all. Think of how you frame them: were there unique skills gained in those projects? Do they lend themselves to showing your capacity for growth, throughout your projects? 

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That all said, if you know and can get advice from someone in the specific department you're applying to, they will be able to give you advice tailored specifically for that program.