design-system

When this skill is invoked:

1. Parse Arguments & Validate

A system name argument is required. If missing, fail with:

"Usage: /design-system <system-name> — e.g., /design-system combat-system Run /map-systems first to create the systems index, then use this skill to write individual system GDDs."

Normalize the system name to kebab-case for the filename (e.g., "combat system" becomes combat-system).

2. Gather Context (Read Phase)

Read all relevant context before asking the user anything. This is the skill's primary advantage over ad-hoc design — it arrives informed.