Use whenever a coding task needs a plan or is hard or risky: new features, changes across several files, refactors, auth, payments or data migrations, or a bug that a fix has already failed to solve (load it together with systematic-debugging). Load it alongside planning, brainstorming or TDD skills, never instead of them; it only decides which model does each part.
Install
npx skills add Gladiarn/Glad-Personal --skill opus-plan-sonnet-buildnpx skills add Gladiarn/Glad-Personal --skill opus-plan-sonnet-build -a claude-code -gnpx skills add Gladiarn/Glad-Personal --skill opus-plan-sonnet-build -a codex -ggemini skills install https://github.com/Gladiarn/Glad-Personal.git --path skills/opus-plan-sonnet-buildgh skill install Gladiarn/Glad-Personal opus-plan-sonnet-buildgit clone --depth 1 https://github.com/Gladiarn/Glad-Personal /tmp/Gladiarn__Glad-Personal
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/Gladiarn__Glad-Personal/skills/opus-plan-sonnet-build ~/.claude/skills/opus-plan-sonnet-build # Claude Code
cp -R /tmp/Gladiarn__Glad-Personal/skills/opus-plan-sonnet-build ~/.agents/skills/opus-plan-sonnet-build # Codex, Cursor, Gemini CLI, Copilot, OpenCode