An agent with the wrong context confidently solves the wrong problem.
Context engineering means supplying the files, errors, contracts, examples, and constraints that change the decision—while excluding noise. Start with the goal, point to sources of truth, and let the agent search outward as needed.
Durable conventions belong in repository guidance. Task-specific facts belong in the prompt. Live external state belongs in tools or connectors. Good context is not maximal context; it is the smallest evidence set that lets the agent reason correctly and verify its result.