Facts and promises
Check names, figures, deadlines and specifications against the source material. If a fact is missing, leave a question for clarification instead of filling the gap with a plausible sentence. Quietly invented business advantages are especially risky.
Context and tone
Text can be grammatically correct and still be wrong for its audience. Remove unnecessary jargon, check that examples are clear and review the action the content suggests. Editing starts with meaning, not individual word replacements.
Readiness for use
Code, text and images need different checks. Code needs its behaviour and constraints tested; text needs facts checked; images need to suit the brief and be cleared for use. Responsibility for publication stays with the person, not the tool.