Context Engineering
Context engineering curates the smallest high-signal token set for LLM tasks. The goal: maximize reasoning quality while minimizing token usage.
When to Activate
- •Designing/debugging agent systems
- •Context limits constrain performance
- •Optimizing cost/latency
- •Building multi-agent coordination
- •Implementing memory systems
- •Evaluating agent performance
- •Developing LLM-powered pipelines
Core Principles
- •Context quality > quantity - High-signal tokens beat exhaustive content
- •Attention is finite - U-shaped curve favors beginning/end positions
- •Progressive disclosure - Load information just-in-time
- •Isolation prevents degradation - Partition work across sub-agents
- •Measure before optimizing - Know your baseline
Quick Reference
| Topic | When to Use | Reference |
|---|---|---|
| Fundamentals | Understanding context anatomy, attention mechanics | context-fundamentals.md |
| Degradation | Debugging failures, lost-in-middle, poisoning | context-degradation.md |
| Optimization | Compaction, masking, caching, partitioning | context-optimization.md |
| Compression | Long sessions, summarization strategies | context-compression.md |
| Memory | Cross-session persistence, knowledge graphs | memory-systems.md |
| Multi-Agent | Coordination patterns, context isolation | multi-agent-patterns.md |
| Evaluation | Testing agents, LLM-as-Judge, metrics | evaluation.md |
| Tool Design | Tool consolidation, description engineering | tool-design.md |
| Pipelines | Project development, batch processing | project-development.md |
Key Metrics
- •Token utilization: Warning at 70%, trigger optimization at 80%
- •Token variance: Explains 80% of agent performance variance
- •Multi-agent cost: ~15x single agent baseline
- •Compaction target: 50-70% reduction, <5% quality loss
- •Cache hit target: 70%+ for stable workloads
Four-Bucket Strategy
- •Write: Save context externally (scratchpads, files)
- •Select: Pull only relevant context (retrieval, filtering)
- •Compress: Reduce tokens while preserving info (summarization)
- •Isolate: Split across sub-agents (partitioning)
Anti-Patterns
- •Exhaustive context over curated context
- •Critical info in middle positions
- •No compaction triggers before limits
- •Single agent for parallelizable tasks
- •Tools without clear descriptions
Guidelines
- •Place critical info at beginning/end of context
- •Implement compaction at 70-80% utilization
- •Use sub-agents for context isolation, not role-play
- •Design tools with 4-question framework (what, when, inputs, returns)
- •Optimize for tokens-per-task, not tokens-per-request
- •Validate with probe-based evaluation
- •Monitor KV-cache hit rates in production
- •Start minimal, add complexity only when proven necessary
Scripts
- •context_analyzer.py - Context health analysis, degradation detection
- •compression_evaluator.py - Compression quality evaluation