Ally scores range from Low to Perfect. The higher the score, the fewer the issues:
Low (0-33%) Needs help! There are severe accessibility issues.
Medium (34-66%) A little better. The file is somewhat accessible and needs improvement.
High (67-99%) Almost there. The file is accessible but more improvements are possible.
Perfect (100%) Ally didn't identify any accessibility issues, but further improvements may still be possible.
Each score also comes with suggestions for how to improve it, unless it's already at 100%.
For more information, visit Accessibility Scores.