Instead of complex SDKs or custom code, users can extend tools like Cowork by writing simple Markdown files called "Skills." These files guide the AI's behavior, making customization accessible to a broader audience and proving highly effective with powerful models.

AI "skills" abstract complex API interactions into simple, accessible recipes. This lets domain experts (e.g., designers who know to use tokens for light/dark mode) codify their specialized knowledge, creating powerful, reusable building blocks for the entire community without requiring engineering knowledge.

Instead of building skills from scratch, first complete a task through a back-and-forth conversation with your agent. Once you're satisfied with the result, instruct the agent to 'create a skill for what we just did.' It will then codify that successful process into a reusable file for future use.

Don't write agent skills from scratch. First, manually guide the agent through a workflow step-by-step. After a successful run, instruct the agent to review that conversation history and generate the skill from it. This provides the crucial context of what a successful outcome looks like.

"Skills" are markdown files that provide an AI agent with an expert-level instruction manual for a specific task. By encoding best practices, do's/don'ts, and references into a skill, you create a persistent, reusable asset that elevates the AI's performance almost instantly.

The three core concepts of Codex Sites work as an integrated system. 'Memory' (a database) stores the state, 'Safe Actions' provide the approved methods for changing that state, and 'Skills' teach other AI agents how to properly use those actions. All three are required to achieve a fully autonomous application.

"Skills" in Claude Code are more than saved prompts; they are named functions packaging a prompt, specific execution heuristics, and a defined set of tools (via MCP). This lets users reliably trigger complex, multi-step agentic workflows like deep chart analysis with a single, simple command.

Treat AI 'skills' as Standard Operating Procedures (SOPs) for your agent. By packaging a multi-step process, like creating a custom proposal, into a '.skill' file, you can simply invoke its name in the future. This lets the agent execute the entire workflow without needing repeated instructions.

Instead of uploading brand guides for every new AI task, use Claude's "Skills" feature to create a persistent knowledge base. This allows the AI to access core business information like brand voice or design kits across all projects, saving time and ensuring consistency.