Context Engineering for Coding Agents: CLAUDE.md, AGENTS.md, and Token Budgets

The agent one-shots your feature on Monday and quietly rewrites your auth module on Tuesday. Here is the workflow that keeps the speed without the wreckage: plan-first prompting, reviewable diffs, and verification the agent runs itself. With interactive tools to grade your own prompts.

Most prompt advice treats every task the same. Real tasks are not the same: a typo fix and a payment refactor need different prompts. Here are four patterns, a way to pick between them, copyable templates, and the anti-patterns that quietly wreck a run.

Discover how TOON (Token-Oriented Object Notation) can reduce LLM token usage by 30–60% compared to YAML, and learn when to use each format for optimal performance and cost efficiency.