What is Context Engineering?
Context engineering is deciding what information an AI system needs and managing it as the work progresses, so outputs are grounded, auditable and less prone to guesswork.
Prompt and context
Prompt engineering is the wording of your instruction to a generative AI model. Context engineering is the broader practice of deciding what information the model needs, what instructions govern the task, and how that material is arranged and maintained as the work progresses. Put simply, prompts steer the style and task, while context provides the material and guidance to reason upon.
For an agent, this continues throughout the task. Context can include tool descriptions and results, retrieved material, memory, and a record of work already done. As the task develops, the system needs to select what remains relevant, update it and summarise or remove what no longer helps.
Better inputs
Strong results come from careful curation. Select a small set of reliable documents, keep them up to date, split them into named sections with a single-sentence summary, and use a simple output schema so the AI maps facts to fields rather than guessing.
Why context matters
It matters now because generous context limits encourage copy-and-paste, which can increase cost and confusion. Tighter, well-labelled inputs produce clearer answers, easier audits and fewer surprises, which is what stakeholders expect from AI.
Sources
Anthropic, Effective context engineering for AI agents
https://www.anthropic.com/engineering/effective-context-engineering-for-ai-agents