Source: Anthropic Engineering
#Why This Article
This is Anthropic's definitive guide to context engineering — the practice that has emerged as the successor to prompt engineering for agent systems. It provides first-party guidance on how to structure the information payload sent to Claude for optimal agent performance.
#Key Takeaways
- Context engineering focuses on finding the smallest set of high-signal tokens that maximize desired outcomes
- Tools should be minimal and non-overlapping — each with a clear, distinct purpose
- Just-in-time retrieval outperforms pre-loading context
- For long-running tasks: use compaction, structured note-taking, and sub-agent architectures
- System prompts should be at the right abstraction level — not too specific, not too generic
#Value for Practitioners
Essential reading for anyone building agent-ready environments. The principles directly inform how to structure CLAUDE.md files, design tool interfaces, and manage context across long agent sessions.