Skills and agents: turning a repeated task into a tool
Every marketing team has tasks that get done the same way again and again. Proofread this copy. Check this claim against its source. Turn this brief into an outline. If you explain the same steps to an AI every time, you're doing work a skill can do for you.
A skill is one workflow. You describe the steps once, in a file, and call it with /skills whenever you need it. It runs inside your current session, so it has your project context. My rule: one skill, one workflow. A skill that does five things is hard to test and hard to fix.
A practical note for anyone who builds skills in Claude Cowork: when you download one, the associated files come with it, even though it doesn't look like they will.
An agent groups related skills. You call agents with /agents, and you describe the process the agent should follow in an .md file. Take a scientific content writer as an example. It might draft the piece, check each claim against the source, proofread, and format the result. Those are separate skills. The agent is the process that ties them together and decides the order.
Try it in planning mode first. Before an agent acts, planning mode shows you what it intends to do. That's where you catch a misread instruction, before it has written 3,000 words.
My rule of thumb for choosing between a skill and an agent:
A single, repeatable task: make it a skill.
A multi-step job that combines several skills and needs its own process: make it an agent.
Where the files live matters too, and I'll cover that in the configuration issue. In short: skills and agents you want in every project sit in your global folders, and ones that only make sense for one project sit inside that project.
Three tips for building AI skills and agents:
1Start from a task you already do well by hand. You can't describe a process you haven't got.
2Write the steps the way you'd brief a new colleague.
Test on real work and fix the skill and agent files, not the output.
Once the skills and agents are defined, they are consistently applied every time.
If you'd like help building skills and agents that fit your team's workflows, get in touch.
Next issue: how to brief an agent like a user story, with a clear definition of done.
Which repeated task in your team would you turn into a skill first?
Previously in this series: