Agent Skills are reusable instruction sets defined to enable AI agents to perform specific tasks or areas of expertise, functioning as modular units that extend the capabilities of an agent.
When AI agents evolve from "general-purpose tools that can do anything" to "specialists that reliably handle specific tasks," the difference comes down to Skills design. Taking Claude Code as an example, Skills are defined as Markdown files. By describing execution steps, tools to use, output formats, and trigger keywords, a user simply saying "write an SEO article" activates the relevant Skill, which handles everything end-to-end — from brief confirmation to writing, quality checks, and database registration. In the OpenClaw ecosystem, over 5,700 community-created Skills are shared on a marketplace. There are even cases where agents write their own code to generate new Skills, and a self-expansion mechanism — where capabilities grow on demand — is steadily taking shape. The key to designing Skills is finding the right granularity. Too coarse, and they become overly generic with reduced accuracy; too fine, and the number of Skills explodes, driving up management costs. In the author's experience, a granularity of "one Skill corresponds to one user action" tends to be just right. While MCP handles the connection between agents and external tools, Skills handle the internal workflow and decision logic within the agent. The two are complementary.


A2A (Agent-to-Agent Protocol) is a communication protocol that enables different AI agents to perform capability discovery, task delegation, and state synchronization, published by Google in April 2025.

Agentic AI is a general term for AI systems that interpret goals and autonomously repeat the cycle of planning, executing, and verifying actions without requiring step-by-step human instruction.

Ambient AI refers to an AI system that is seamlessly embedded in the user's environment, continuously monitoring sensor data and events to proactively take action without requiring explicit instructions.
