How to create a Copilot agent in Microsoft 365, step by step

You can build a working Copilot agent in about twenty minutes without touching Copilot Studio. The agent builder inside Microsoft 365 Copilot handles most everyday agents, and the part that decides whether it is any good is the instructions, not the tool.

Here is how to create a Copilot agent, step by step. Menu names shift between updates, so if a label looks different on your screen, look for the nearest match.

Before you open the builder

Answer three questions on paper first:

1. What one job does it do? "Writes the weekly status update", not "helps with projects".
2. What does a good output look like? Find one real example.
3. Which documents does it need? Two to five, not a whole site.

Step 1: Start a new agent

In Microsoft 365 Copilot, open the agents area in the side panel and choose to create an agent. You will usually see two ways to build: describing it in conversation, or configuring it directly. Use configure. It is faster and you control every word.

Step 2: Name and describe it

Name it after the job: "Weekly Status Writer". The description is what colleagues see when they find it, so write one plain sentence about what it does and when to use it.

Step 3: Write the instructions

This is where most agents succeed or fail. Use four parts:

WHO YOU HELP
You help [team] with [one job].

WHAT YOU PRODUCE
[Output], in this format: [structure, length].

HOW TO DECIDE
Use the attached [documents] as the source of truth. If
information is missing, list what is missing first, then draft
with [PLACEHOLDER] markers.

NEVER
- invent numbers, names or dates
- [the habit you most want to prevent]
- answer questions outside [the job]; say it is out of scope

Keep it under 2,000 characters to start. You can always add; it is harder to diagnose a long instruction that is not working.

Step 4: Add knowledge

Attach the few files or the single SharePoint folder the job needs. Less is better: a narrow set makes answers sharper and easier to trust. Only add web search if the job genuinely needs current public information.

Step 5: Add starter prompts

Write three or four prompts people will actually use, like "Draft this week's update from these notes". They double as a user guide.

Step 6: Test it properly

Use the test pane with three kinds of request:

• A normal one. Does the output match your good example?
• One with missing information. Does it ask or flag, rather than invent?
• One out of scope. Does it decline politely?

Fix the instructions after each test. Two or three rounds is normal.

Step 7: Create and share

Create the agent, then share it with the people who need it, if your organisation allows sharing. Check they can open the knowledge files; an agent answers differently for someone who cannot see its sources.

When you do need Copilot Studio

Move to Studio when the agent has to take actions in other systems, run multi-step workflows, or be published to channels outside Microsoft 365. For drafting, answering and summarising, the builder is enough.

Questions people ask

Do I need a Copilot licence to create an agent?

Agent creation and what agents can access depend on your licence and your admin's settings. If you do not see the option, ask IT what is enabled.

Can a Copilot agent read my email?

Only within the permissions your organisation allows. Knowledge sources you attach are the most reliable way to control what it uses.

How do I update an agent later?

Open it from your agents list and edit. Changes apply for everyone you have shared it with.

Where to take this next

For eight ready-made agents to build next, see Copilot agent examples, or grab the free Microsoft 365 Copilot agent config pack. For agents written around your specific role, The Pack includes a Copilot install path.