> Looking up official documentation would require shipping sophisticated parsers for each language,

You could just token match (use tree-sitter or something similar) and fetch the official docs. Keep it dead-simple so there's no way you can provide false positives (unlike what's happening rn where hallucinations will creep in).

> It generates explanation

Again, I don't want that. It's not a feature, it's a limitation that right now gives you fake information.