The "annotation text"/comments is what annotation really is about. Any engine can say how good it believes moves to objectively be, but what makes the game unique and "human" is the comments. As far as chess symbols like "+-" or "=", I almost never use them. I know what they mean, but many do not. If I use those symbols, then I'll usually even have a short comment with it. Something like "White has a space advantage that is important +-" or something like that.
The symbols I use a bit more often are "!!", "!", "!?", "?!", "?" and "??" because they are a lot more well known 
Hi guys,
I annotated my first game with symbols. Is it already good or can it be improved upon? Is it worth expanding on by adding text? What do you think?