Set up your skills kit
in Microsoft 365 Copilot

Before we start

There are two products called Cowork

A naming collision worth clearing up front. Microsoft 365 Copilot Cowork - the subject of this guide - is the agentic mode in the Microsoft 365 Copilot app, generally available worldwide since 16 June 2026. Claude Cowork is Anthropic's agentic surface in the Claude apps, available on Pro plans and up. Same word, two separate products.

The useful part of the overlap: both read skills in the same SKILL.md format, so the kit in this guide runs in either one without changes. This post covers the Microsoft side. For the Claude side, the setup lives in the Claude version of this guide.

The shift: one file per job, read every session

A skill is a folder holding one SKILL.md file - a name, a description that tells Copilot when the skill applies, and the full instructions for one job: inputs, method, output layout, and the rules that never bend. Put it in the Cowork skills folder and it runs the same way every time, for every client, without a single paste.

Worth stating plainly: SKILL.md is the same format Claude skills use. Microsoft adopted the existing format rather than inventing a rival one, which makes it a de facto standard - and means a skill you write today is an asset you keep even if you change AI tools later. The kit below is the proof: identical files, three platforms.

Running a skill in Cowork

Start a Cowork session and either name the skill - "Run the meeting minutes skill on the transcript in the Acme folder" - or just describe the job. Each skill's description tells Cowork when it applies, so "turn these notes into minutes I can send" finds the right skill on its own. Skills are discovered fresh each session, so anything sitting in the skills folder when you start is available.

A few working boundaries to know. Cowork operates on OneDrive and SharePoint files only - it can't reach files on your local machine, so anything you want worked on goes into OneDrive first. It can't delete files, which makes it hard for a task to do real damage. And it reads .md natively, so skill files and markdown outputs need no conversion. The limits are generous for a kit this size: 50 custom skills, 1 MB per SKILL.md, and up to 20 companion files totalling 10 MB per skill if a skill needs templates alongside its instructions.

To hand a skill to a colleague, share it from Cowork with the specific people who need it - sharing is per skill, not all-or-nothing. If you'd rather upload than sync a folder, Cowork also accepts skills as .md, .zip or .skill archives.

The fallback: a skills agent, if Cowork isn't enabled yet

Cowork is off by default and admin-gated, so some readers will have a Copilot licence and no Cowork toggle. There's a workable interim: build one shared skills agent in Agent Builder, inside the Microsoft 365 Copilot app. Any business user can build one - no code, no admin rights, unless your admin has disabled the feature tenant-wide.

1. Instructions - paste the master instructions into the agent's instructions field. It takes up to 8,000 characters, which fits the master file with room to spare.
2. Knowledge - convert each SKILL.md to .docx or .txt and embed the files as the agent's knowledge. Agent Builder accepts around 20 knowledge sources, so ten skills fit; it doesn't accept .md uploads, hence the conversion.
3. Share - share the agent with specific people or the whole org. Embedded files travel with the agent, visible to everyone who has it - so keep client material out of it and let the agent stay client-neutral.

Creating your own skill

The ten skills cover the standard consulting arc, but your practice has jobs of its own - a board pack, a tender response, a workshop agenda. Any job you've done the same way three times is a skill waiting to be written. The fastest way to write one is to ask Copilot to draft it. Copy this prompt and fill in the brackets:

You write skills for Microsoft 365 Copilot Cowork. A skill is a
folder holding one SKILL.md file: YAML frontmatter with a name and
a description that says when the skill applies, then the
instructions in markdown.

Draft a new skill for this repeatable job: [describe the job - what
comes in, what should come out, who reads the output].

Structure the instructions in five sections:
1. What this does
2. What you give it
3. How to do the work
4. Output layout
5. Rules

Make every instruction specific enough that the output looks the same
no matter who runs it. Before drafting, ask me up to three questions
if anything about the job is unclear.

When you're happy with the draft: create a new folder inside OneDrive > Documents > Cowork > skills, named after the skill, and save the draft into it as SKILL.md. Save a copy into your master Skills folder too, so the source of truth stays complete. The new skill is discovered at your next Cowork session, exactly like the ten that came with the kit.

Editing a skill: the update loop

Skills improve with use. The first time a status report comes out with a section you always delete, that's not an annoyance - it's an edit waiting to be made. The loop here is the shortest of the three platforms:

1. Edit the master - open the skill's SKILL.md in your master Skills folder on your computer and change it there. Never anywhere else.
2. Copy it over the OneDrive version - replace the SKILL.md in OneDrive > Documents > Cowork > skills with the edited one. Your next Cowork session picks up the new version automatically.