Good Sign:

1. Roadmap - there should be at least a roadmap and what the project wants to accomplished. At least a good 3 - 6 months project pipeline.
2. The team - the devs or the top management should be also has a name and a face in the Whitepaper so that we can verify if they are really legit or not.
3. Jargon - not too much technical terms, because most investors will not understand it anyways. Brief concise and straight to the point.

Bad Sign:

1. Spelling mistakes - If I found some spelling or grammar mistakes, I tend to stay away because it doesn't look professional. They are asking investors to pour money on them and yet they can't even proof read their paper
2. No teams mentioned. - very shady to me