What 466 AGENTS.md files teach about context engineering
An MSR 2026 study of 466 open source projects maps the five modes developers use to write AGENTS.md context, and what 50% file staleness reveals about practice.
Further reading
Articles about Prompt Engineering
5 articles from the Wire blog, sorted newest first. Return to the Prompt Engineering definition for context.
Agentic context engineering: how ACE evolves contexts
ACE (ICLR 2026) beats tuned prompts by 10.6% with self-evolving contexts that avoid brevity bias and context collapse, two real failures of prompt tuning.
TOON vs JSON: why smaller doesn't mean cheaper for LLMs
TOON looks more compact than JSON, but a 9,649-test study found it cost LLMs 38% more tokens. The reason: model training distribution beats format size.
Context engineering: the end of prompt engineering
Prompt engineering is a dead end. Context engineering — designing what information AI models receive — is replacing it. Here's how to start applying it.
Context engineering: what replaces prompt engineering
Prompt engineering has a new successor: context engineering. Learn why Karpathy and Tobi Lütke made the switch, and what it means for production AI systems.
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