v3.1.0 — 2026 model guidance overhaul

2026 model guidance overhaul. No breaking changes.

What changed and why

budget_tokens removed — Claude 4.7+ returns HTTP 400 when budget_tokens is set in the request. Any skill that used this field stopped working on current models. Replaced with output_config.effort. (#32)

references/model-guidance.md expanded 90 → 350 lines — the short existing guidance was insufficient for the Fable 5 / Opus 4 / Sonnet 4 / Haiku 4 generation. Added: what changed in 2026 for skill authors (over-specification now actively hurts; Fable 5 self-routes without rigid scaffolding), tier-specific instruction density calibration, and guidance on when to use extended thinking. (#32)

SKILL.md compressed 519 → ~415 lines — removed prescriptive boilerplate that told the model how to think instead of what done looks like. The compression came from replacing multi-step sequences with outcome descriptions. This is the "less is more" lesson from Fable 5 evaluation: rigid step sequences suppress the model's own reasoning and reduce quality on harder tasks.

Hedged language flagged — lint now flags phrases like "try to", "if possible", and "consider" as producing optional compliance. A skill instruction that says "try to validate input" is a suggestion, not a requirement. The linter treats these as warnings so authors can make the intent explicit.

PRs

#32