People noted similar issues ever since LLMs came out, but the rate at which they have been rapidly improving on all of these is significant. Documentation being 4x too long could probably be fixed with a rule instructing the agent to keep it concise and no longer than 2-3 paragraphs.
Conciseness is variable. Sometines a paragraph is enough, some other tome you need multiple chapters and a glossary to get the point accross. 4x too long may be 4 paragraphs in the first case and a 400 pages book in the second case.
Adding a rule like yours is not the solution.
They seem to be converging toward an asymptotic accuracy level that is not particularly close to 100%. That is not good enough when you're trying to instruct engineers, particularly junior ones.