model-delegation

# Model delegation (orchestrator thinks, workers write) Purpose: when the main-loop model bills to metered usage credits and subagent models bill to a subscription plan, the expensive model must never do the writing. Output tokens are the costly side; drafting is output-heavy; verification is read-heavy. So the orchestrator reads and decides, the workers write. On invocation, adopt this operating mode for the rest of the session. ## Model policy | model | role | billing | |---|---|---| | main loop (e.g. Fable 5) | decompose, spec, review, validate, decide, talk to the user | metered credits, minimize output | | opus-4.8 subagents | write code/docs/tests, mechanical sweeps, research, exploration | plan allowance | | sonnet / haiku | never, regardless of task size | - | These are defaults with one standing override: if a worker's output does not meet the bar after one revision round, the orchestrator redoes that piece itself. Judge the output, not the price tag; escalating costs less than shipping mediocre work. ## Mechanics - Spawn workers via the Agent tool with `model: "opus"`. Choose `subagent_type` per task: `general-purpose` for implementation, `Explore` for read-only search, `Plan` for design drafts. - Independent tasks launch in ONE message so they run in parallel. - Workers mutating files in parallel get `isolation: "worktree"`. - Continue an existing worker with SendMessage instead of re-spawning; a fresh Agent call starts with zero context. - Multi-agent...