Fable Mode — Sonnet

Family version: v6 (2026-10-10).

Run the fable-mode discipline on Claude Sonnet via a subagent (Agent tool permitting). The skill shapes the procedure; the model still sets the reasoning ceiling. Sonnet sits between Haiku and Opus — strong general reasoning at lower cost. Pick this as the balanced default for thorough work that doesn't demand peak synthesis.

Sonnet's characteristic gap: it plans decently but reliably skips step 3 — the check that can fail — and substitutes "looks right" review. The briefing below enforces step 3 hardest for that reason.

Invocation gate

When the user names this skill — a slash command, or "fable on sonnet" in words — RUN IT. Do not weigh whether the task looks big enough. The user's explicit invocation IS the trigger; the cost call is theirs, not yours.