Automation Shape Routing — Workflow vs ATM vs Skill

HEADLINE TRAP — don't orchestrate a one-shot task. Before standing up ANY ATM swarm or Workflow, ask: is this a reusable automation, or a single deliverable I just need produced once? A one-off task ("generate 9 content ideas", "draft this section", "summarize these files") is not an automation — orchestrating it stands up machinery that costs more time than the task. The verdict for a one-shot is shape 0 below: do it inline, or fan out 2–3 in-session Agent subagents. Real failure (2026-06-15): an operator pointed a heavy ATM-codex swarm at a ~9-idea content task; it wedged on codex boot and cost more than doing it inline would have. In-session Agent fan-out later worked in one pass. If you are reaching for ATM or a Workflow, confirm you are not here.

The other trap this kills: "I built a lot of skills; they should become workflows." Mostly false. Most orchestration-looking skills are either long-lived/human-attachable (stay ATM) or hard-sequential (stay skills). The win is the routing rule, not a migration project.