https://martinfowler.com/articles/exploring-gen-ai/context-engineering-coding-agents.html
Instructions: Prompts that tell an agent to do something, e.g. “Write an E2E test in the following way: …” Guidance: (aka rules, guardrails) General conventions that the agent should follow, e.g. “Always write tests that are independent of each other.”
Part of Context Engineering. See also LLMs, Coding agents.