The framing of "constraints over instructions" at Level 6 is the most underrated point here. In my experience, the reliability jump from telling an LLM "always output valid JSON" vs. giving it a typed schema with static validation is night and day — especially with smaller models. I'd argue that levels 3-5 deserve more weight than the post gives them. The gap between someone who has internalized context engineering and someone who hasn't is larger than the gap between levels 7 and 8. Most failures I see in agentic systems aren't from insufficient autonomy — they're from poorly structured prompts and tool descriptions that compound errors downstream. The foundation work is less glamorous but it's where the leverage is.The "decouple the implementer from the reviewer" principle is spot on. Same model reviewing its own output is basically asking someone to proofread their own essay.