Claude Code

Everybody talks about prompt engineering. Write better prompts, get better results. That framing was useful once, but it misses the point for coding agents. The prompt is maybe five percent of what determines whether a session goes well or falls apart. The rest is context: what the agent sees when it starts working, how that context evolves over the session, and what happens when it grows too large for the model to track. Andrej Karpathy named this “context engineering” in mid-2025, and the term stuck because it describes something real. You’re not just writing prompts. You’re engineering the entire information environment the agent operates in. That includes your project structure, your AGENTS.md files, the git state, the conversation history, and everything the agent discovers as it works. Get this right and the agent feels like a capable collaborator. Get it wrong and you’ll spend more time correcting it than doing the work yourself.

Claude Code skills let you extend a coding agent with custom workflows, specialist knowledge, and automation. You write a SKILL.md file with instructions, and the agent follows them. At least, that’s the idea. In practice, Claude treats skill content as advice, not as instructions. A skill that says “always use spec-kit to create the specification” might get followed, or Claude might decide it already has enough context from the brainstorming phase to write the spec directly. It’s being helpful, but it’s also wrong. This post describes patterns for dealing with that challenge, from scripts that enforce consistency to hooks that block shortcuts before they happen.