They will chew at the bars. The paint must be non-toxic. Birds are notorious for opening birdcage latches. The latch must be of a good design and secure. Keeping a cage clean and sanitized is a very important issue.
Some cages are impossible to keep clean, even harder yet to sanitize.
The cage must be the proper size for the bird. The larger the better. I won t buy a cage unless it has a playpen on top. Cages are fine when you re not around to watch the bird. But birds need their freedom.