How to Create a Custom Agent in Microsoft 365 Copilot: A Complete Guide

In 2024, Microsoft retired the consumer-focused "Copilot GPT Builder" and redirected its artificial intelligence efforts entirely toward the corporate and enterprise environment. The result of this evolution is the new Copilot Agents, deeply integrated into the Microsoft 365 ecosystem.

Whether you want to build an HR assistant that answers questions based on policies saved in SharePoint, a sales copilot that summarizes Outlook emails and CRM data, or a technical support agent trained on your team's manuals: Copilot Agents act as focused collaborators integrated into your daily workflow.

The best part? You don't need to write code. With the new Agent Builder integrated into Microsoft 365 Copilot, you can build bespoke assistants by chatting with the AI or defining manual parameters. In this step-by-step guide, you will learn how to create, configure, and publish your own Copilot Agent, and discover when it makes sense to migrate to external customer service solutions on open channels like Tolky.

What is an Agent in Microsoft 365 Copilot?

An Agent in Copilot is a specialized version of Microsoft's AI designed to execute specific tasks in the context of your work. It combines custom behavioral instructions, secure knowledge bases (SharePoint data, OneDrive, local files), and action capabilities (data interpretation, web searches).

Unlike standard Copilot (which searches general web data or responds without a restricted scope), an Agent is focused. If you create a "Contract Review Agent" and limit it to a specific SharePoint folder, it will only use that corporate information to respond, reducing the risk of hallucinations.

For companies strategically planning their processes, here is how Copilot Agents differ from other solutions:

Important note on licensing: Creating agents via the Agent Builder generally requires a paid Microsoft 365 Copilot license (not just the free version or the discontinued consumer "Copilot Pro"). For highly complex agents that access third-party APIs, Microsoft recommends using Copilot Studio, a separate and more robust low-code tool.

How to Create a Copilot Agent: Step-by-Step (Agent Builder)

If you have the appropriate license, you can create agents directly in the Microsoft 365 web apps (like office.com/copilot).

Step 1: Access the Agent Builder

1. Open Microsoft 365 Copilot in your browser or app.
2. In the navigation pane or sidebar, look for the option to view your agents or click on New agent.
3. This will open the Agent Builder interface.

The builder has two main tabs: Describe, where you can simply tell the AI what you want to build and it pre-fills the settings, and Configure, where you manually define the rules precisely. On the right, there is a test panel (Test your Copilot) to validate the agent before publishing.

Step 2: Go to the "Configure" Tab for Maximum Control

While the Describe tab is useful for rapid prototyping, manually filling out the Configure tab ensures your agent has predictable and secure behavior, without confusing auto-generated prompts.

Agent Builder Configuration Interface in Microsoft Copilot

Here, you will fill in these structured fields:

• Name: Your agent's name (e.g., Tolky B2B Assistant).
• Description: A clear description explaining the bot's purpose to your teammates (e.g., Assisted support for B2B integrations and API documentation).
• Instructions: The behavior engine of the agent, where you detail rules, tone of voice, and restrictions.

Step 3: Write Structured Instructions

To ensure the agent does not invent information (hallucinate) and meets corporate standards, structure your instructions using Markdown. Here is a real-world example:

## Objective and Profile
You are "Tolky B2B Support", an expert agent focused on helping corporate clients and internal teams with the integration, configuration, and troubleshooting of our B2B APIs.
 
## Tone and Behavior
- Be highly professional, clear, empathetic, and focused on technical solutions.
- Format responses using markdown for code blocks and numbered lists for step-by-step guides.
- Avoid personal opinions and informal slang.
 
## Knowledge and Boundary Guidelines
- Provide structured technical responses *exclusively* based on the sources provided in the Knowledge section (SharePoint and files).
- If the answer is not in the documentation, politely inform: "I couldn't find that specification in the official documentation. I suggest contacting specialized human support."
- Your scope is strictly B2B integrations. Do not answer generic IT or HR questions.

Step 4: Connect Knowledge Bases (Knowledge)

This is the most powerful step within the corporate ecosystem. Under Knowledge, you connect the actual data the agent will use:

1. Click Add Knowledge.
2. You can select entire SharePoint sites, specific folders, or files from your OneDrive.
3. You can also manually upload files directly from your computer (like api-docs.pdf or integration-guide.docx).

By focusing the agent on specific SharePoint folders, you ensure that responses are always up to date with your company's current policies, taking advantage of Microsoft's established corporate security.

Step 5: Enable Necessary Capabilities

In the lower Capabilities section, activate the additional tools your agent will need:

1. Web Search: Allows fetching up-to-date internet data.
2. Code Interpreter: Essential for agents that will analyze complex spreadsheets, mathematical data, or generate charts based on files.
3. Image Generation: Enables creating images on demand using Microsoft's integrated AI model.

Step 6: Test and Publish

Use the right-hand testing panel (Test your Copilot) to send messages to your agent.

Real-time testing (Preview) of the Copilot Agent

Verify if it:

• Returns responses based solely on the linked SharePoint files.
• Respects the defined tone of voice.
• Cites its sources at the end of each generated response (an important standard of Microsoft Copilot).

Once satisfied, click Create or Publish. You can choose to share the agent only with yourself, with specific members of your team, or with the entire organization via a link.

The Leap to Customer Service (Omnichannel)

Creating an Agent in Microsoft 365 Copilot is a fantastic way to boost the productivity of internal teams, creating active knowledge libraries and routine assistants.

However, Agents created in the Agent Builder are, by design, intended for internal organizational use. If your goal is to scale external end-customer support through channels like WhatsApp, Instagram, or a chat on your corporate website, and if there is a need for dynamic integrations with market CRMs and immediate handoffs to human operators, Microsoft directs that complexity to heavier use of Azure or the advanced Copilot Studio.

It is exactly to simplify omnichannel external customer service that Tolky was developed.

Combining the ease of creating "no-code" agents with modern Contact Center functionalities, Tolky allows your agent to access dynamic data securely and serve your customers where they are, with comprehensive management dashboards and transfer to human support.

If you are ready to transform your customer service efficiency into tangible results, schedule a practical demo with our team and let's build your Intelligent Brand Avatar on Tolky!

Suggested internal links:

• How to Create a Corporate Chatbot with Generative AI without Depending on IT
• What is Agentic AI and Why It Will Redefine Business Automation
• Agent Orchestration: Architecture and Best Practices