Addy Osmani's agent-skills — Senior Engineering Practices as SKILL.md Files

Addy Osmani (Google Chrome engineering lead) packaged senior engineering practices into 20 core skills that AI coding agents can follow. The insight: AI agents naturally take shortcuts — skipping specs, tests, and security reviews. These skills enforce the discipline that experienced engineers bring to every project. Its rapid GitHub adoption has made it a reference implementation for encoding engineering culture into agent workflows.

The 7 Slash Commands

Each command maps to a phase of the software development lifecycle:

Six Development Phases, 20 Skills

Phase 1: DEFINE
├── idea-refine
└── spec-driven-development

Phase 2: PLAN
└── planning-and-task-breakdown

Phase 3: BUILD
├── incremental-implementation
├── test-driven-development
├── frontend-ui-engineering
├── api-and-interface-design
├── context-engineering
└── source-driven-development

Phase 4: VERIFY
├── browser-testing-with-devtools
└── debugging-and-error-recovery

Phase 5: REVIEW
├── code-review-and-quality
├── code-simplification
├── security-and-hardening
└── performance-optimization

Phase 6: SHIP
├── git-workflow-and-versioning
├── ci-cd-and-automation
├── deprecation-and-migration
├── documentation-and-adrs
└── shipping-and-launch

Plus 3 specialist agent personas (code-reviewer, test-engineer, security-auditor) and 4 reference checklists.

What Makes These Skills Special

Each SKILL.md follows a standardized structure with an “anti-rationalization table” — anticipating shortcuts agents try to take:

Google Engineering Culture Encoded

The skills draw heavily from Software Engineering at Google:

• Hyrum’s Law in API design — backward compatibility matters
• The Beyonce Rule in testing — “If you liked it, you should’ve put a test on it”
• Chesterton’s Fence in code simplification — don’t remove what you don’t understand
• Change sizing norms (~100 lines) in code review
• Trunk-based development in git workflow
• Shift Left principle in CI/CD — catch problems early

Installation

# Claude Code
/plugin marketplace add addyosmani/agent-skills
/plugin install agent-skills@addy-agent-skills

# Gemini CLI
gemini skills install https://github.com/addyosmani/agent-skills.git --path skills

# Cursor / Windsurf / Copilot
# Follow the repo's tool-specific setup docs for rules, agent definitions, or instructions files.

# Manual (any agent)
git clone https://github.com/addyosmani/agent-skills.git

Skills are plain Markdown — any agent accepting system prompts can use them.

How LearnAI Team Could Use This

• Teaching software engineering — the 6-phase lifecycle is a pedagogical framework itself
• Improving AI-assisted student projects — install the skills to enforce best practices
• Studying skill design patterns — the anti-rationalization table is a novel concept worth teaching
• Building custom skills — use this repo as a template for encoding domain expertise

Real-World Use Cases

• Engineering teams — enforce consistent practices across all AI-assisted development
• Open source projects — standardize contribution quality regardless of agent used
• Junior developers — learn senior-level practices by reading the skill files
• Code review — the reviewer agent persona provides structured, opinionated feedback <!– REVIEW-TODO: [source_links] Weibo source link is generic (https://weibo.com), not a specific post URL — find actual post or remove –>