4.2What Can Be Automated vs What Cannot

Can Be Automated	Requires Human Judgment
Missing alt text on images	Whether alt text is meaningful
Color contrast ratios	Whether color conveys meaning
Missing form labels	Whether label text is clear
Missing ARIA roles	Whether ARIA roles are correct
Keyboard focusability	Whether focus order is logical
Heading hierarchy (h1-h6)	Whether headings describe content
Lang attribute present	Whether language is correct for content
Link text exists	Whether "click here" is descriptive enough
Duplicate IDs	Whether ID references are semantically correct
Table headers present	Whether data tables are structured logically

The 30/70 Split

Automated tools catch the "is it present?" questions. Humans (or AI agents) must answer the "is it correct?" questions.

Automated: "Does this image have an alt attribute?"  -> Yes/No
Human:     "Does the alt text accurately describe the image for
            someone who cannot see it?"                -> Judgment required

Automated: "Is the color contrast ratio >= 4.5:1?"   -> Yes/No
Human:     "Is color the ONLY way this information
            is communicated?"                          -> Judgment required

Automated: "Does this form input have a <label>?"    -> Yes/No
Human:     "Does the label clearly explain what
            the user should enter?"                    -> Judgment required