We’ve moved far beyond prompt engineering. Now we’re designing portfolios of tools (directory listing, file editing, web search), slash commands like /pr-create that inject prompts vs , specialized sub-agents @pr-creation-agent, vs having an AGENT.md with systems that work across IDEs, command lines, GitHub, and Slack.

Context engineering is designing tool responses and interaction patterns that give agents situational awareness to navigate complex information spaces effectively.

To understand what this means practically, let’s look at how systems have evolved:

Before: We precomputed what chunks needed to be put into context, injected them, and then asked the system to reason about the chunks.
… Now: Agents are incredibly easy to build because all you need is a messages array and a bunch of tools.  — Read More