Step-by-step SKILL.md packages an AI follows for a single kind of task.
A skill is a focused playbook - instructions, examples and constraints - that makes any model reliable at one job, from SQL reporting to changelog writing. The router fills a plan's skill slot with the best match for the request.
Makes operations safe to repeat so retries and at-least-once delivery don't double-charge or double-create — idempotency by design first (PUT/upsert, conditional writes with version/ETag/If-Match, nat
