Chapter L5.3 — Skills in operation in Cowork

Level 5 — Skills and identity. Product details verified on 24/06/2026 against official sources.

Goal

By the end you’ll know how to use Skills in autonomous work: how they behave in chat versus Cowork, why it’s worth splitting them into several focused skills instead of one big one, and how to share them in a team. The guiding example is the three skills this book is written with.

Prerequisites

• Knowing how to create a skill (ch. L5.2).
• Knowing Cowork (ch. L3.1).

In chat and in Cowork

The same skill is valid in chat, in Cowork and in Claude Code: you write it once and it guides Claude the same way everywhere. What changes is the context it works in.

In chat the skill refines a single response: tone, format, structure. In Cowork, where Claude runs a long task on a folder across multiple steps, the skill counts for more: it governs a behavior repeated over many files, without your having to repeat the rules at every step. The more autonomous and long the work, the more a well-written skill makes the difference between a consistent result and one that depends on how precise you were today.

Splitting instead of piling up

The temptation is to write one skill that does everything. It’s almost always a mistake. Several focused skills compose better than a monolithic one, for two reasons: the description of a targeted skill triggers precisely (ch. L5.1), whereas that of a do-it-all skill is necessarily vague; and Claude can combine several skills automatically when they’re needed together.

Rule of thumb: one skill, one workflow. If you notice a skill has two distinct purposes, split it. Skills can’t call one another, but Claude uses several in the same task: the composition is done by it.

Example: the three skills of this book

This manual is written with three separate skills instead of one big one:

• voce — tone and terminology: plain, direct prose, product terms in English, no brochure-style enthusiasm.
• struttura-capitolo — standard structure, length target, use of the facts ledger, definition of done.
• vincoli-a5 — layout constraints: narrow code, three-column tables, vertical diagrams.

Each has a clear purpose and a description that triggers on its scope. When I write a chapter, Claude uses all three together: voice governs the text, structure the skeleton, constraints the form. A single skill that did the work of all three would be harder to write, to trigger and to update.

Figure L5.3.1 — Three focused skills that Claude composes on a chapter. Alt text: vertical diagram with three skills converging on the writing of a chapter.

Sharing in a team

A useful skill shouldn’t stay on your account. On the Team and Enterprise plans an administrator can provide and manage skills for the whole organization, so everyone works with the same rules. It’s the way to make a standard — of voice, of format, of process — something that holds for the group and not just for whoever wrote it.

Tip: before sharing a skill in a team, have someone else try it on real prompts. A description that triggers well for you may trigger badly for someone who uses different words.

In practice: bring your skills into Cowork

1. Start from a workflow you repeat often in Cowork (e.g. organizing assets, producing a report).
2. Write its rules in a focused skill (ch. L5.2).
3. If the purposes are two, make two skills, not one.
4. Activate it and launch a task in Cowork: verify that the rules are applied.
5. If you’re in a team, ask the admin to make it available to the organization.

Common mistakes

• The do-it-all skill. Vague description and hard to maintain. Split by workflow.
• Expecting one skill to call another. It doesn’t happen: it’s Claude that composes them. Write them self-contained.
• Sharing without having it tested. In a team, a description should be tested on several ways of writing the same intent.
• Repeating the rules in the prompt. If they’re in a skill, there’s no need to restate them in every task.

Summary

1. The same skill is valid in chat, Cowork and Code; in Cowork it weighs more because it governs long, autonomous tasks.
2. Several focused skills compose better than a monolithic one.
3. Skills don’t call one another: the composition is done by Claude.
4. The three skills of this book (voce, struttura, vincoli) are the example of the pattern.
5. In Team/Enterprise an admin shares the skills with the whole organization.

Next step

In ch. L5.4 — Making Claude sound like you we put together all the identity tools — instructions, Projects, context files and Skills — to give Claude your voice in a stable way.

Data on use, composition and sharing of skills verified on 24/06/2026 on support.claude.com/en/articles/12512198. The example of the three skills is real (they’re the ones from this book’s project). No skill executed here.