What problem does it solve? AI agents degrade as context windows fill: attention dilutes, critical instructions get lost in the middle, and token costs balloon. This Skill provides the foundational mental models and concrete utilities to design, budget, and debug context for agent systems. ## Core Features & Use Cases - Context Engineering Principles: Covers attention budgets, the lost-in-the-middle effect, progressive disclosure, position-aware placement, and compaction triggers at 70-80% utilization. - Context Management Utilities: A Python module offering token estimation, priority-aware context assembly (ContextBuilder), message truncation, structure validation, and lazy file loading (ProgressiveDisclosureManager). - Technical Reference: Detailed guidance on system prompt sectioning, tool description engineering, document chunking, observation masking, and context budget allocation tables. - Use Case: When an agent's reasoning quality collapses after 20-30 tool calls, use this Skill to diagnose history bloat, apply observation masking, and set compaction triggers before the window fills. ## Quick Start Ask the agent to explain how to design a context budget for a new agent system and review your current system prompt structure.