Progressive disclosure

Progressive disclosure is loading detail in tiers, so only what a branch actually reaches gets loaded. The Agent Skills format quantifies it, and Anthropic publishes the table: name and description at startup at roughly 100 tokens per skill, the SKILL.md body under 5,000 tokens once the skill is triggered, and bundled scripts and references at no cost at all until something reads them. It is not primarily a token optimisation — it is how the top of a document stays legible.