The ICE Plugin — an open-source Claude Code plugin packaging the ICE planning framework (Intent, Constraints, Expectations) as a distributable skill for the Claude Code marketplace. ICE structures planning conversations between human and AI before implementation begins, surfacing requirements through structured dialogue, enforcing critical review, and producing a documented blueprint. It reduces agreement bias and vague-input failures. The plugin packages the following skills: /ice — Full ICE planning session with blueprint output /q — Clarifying questions before starting work /challenge — Challenge assumptions from hostile positions /verify — Sceptical review of AI output before accepting