[mkozlows]

No. Many of the things that automated tools can't find are simply impossible to judge in an automated way. Alt text being appropriate for images, for instance, is something that has to be verified by a human (or an AI that's indistinguishable from one).

[scott_s]

Hmmm. Facebook is already automatically adding alt text to uploaded images (http://www.theverge.com/2016/4/5/11364914/facebook-automatic...). I think it's within reason to do a comparison of that generated text with the real text, and come up with a score of how likely it is to be representative.