Part 2: Prompts, context windows and Claude skills

Module 10 · Sun 20 Sep

A system prompt is the hidden layer that sets behaviour; the user prompt is the immediate request. Real apps layer both. The context window is how much the model can actively use - long chats run out, so compaction (summarising old context) frees space. A chat is not infinite memory.

• Prompting isn't about more words. Keep it specific, cut filler, use delimiters/tags for long prompts, and remember the middle of long prompts gets "lost" (attention dilution).
• Temperature controls randomness - separate from how you word the prompt.
• Claude skills are reusable Markdown instruction files, picked by matching your request to the skill description. Best when each skill does one job.

Class build - a PRD system prompt: role, guardrails, tone, audience, problem, pain points, user stories, design, functional and non-functional requirements, user flow, success metrics - plus the sections the PM must truly own. Delimiters help even with voice input: ask the model to restructure spoken text into sections.