Sales Agent Extensibility - 5 Build Lessons

Angeliki Patsiavou
23 hours ago
4 min read

Agents! Agents! Agents! It is like the more we say it, more of them come out! Especially in Sales, we have seen an exponential increase not only in agents but also features. Which is fantastic for us Dynamics 365 geeks!

Before we get to the heart of this blog post…

A short recap of the cool agents available, with some still in preview:

Sales Research Agent: (Backed by our old friend Project Sophia) Answers complex questions about our CRM data using natural language and generates insights from accounts, opportunities, and activities.
Sales Qualification Agent: Automates lead qualification, research, and initial outreach to determine if a lead should enter the pipeline.
Sales Close Agent – Research: Continuously analyses opportunities to surface insights, risks, and signals that can help sellers progress deals.
Sales Close Agent – Engage: Interacts with prospects during the opportunity stage. This includes sending outreach, handling objections, and help us drive the deal toward closure.
Sales Agent (in Microsoft 365 Copilot): Allows us to query and analyze sales data across CRM and Microsoft 365 (emails, meetings, docs) via natural language to prepare for accounts and opportunities across the pipeline.

Alas, this is not what this blog post is about.

This post is a simple Public Service Announcement for those curious souls wanting to extend the Sales agent.

A long time ago, we used to be friends…

There are some key points and caveats when it comes to extensibility. Here are the key ones. Let’s demystify them!

Lesson 1: You cannot just click on the main Create blank agent area in Copilot Studio

What? What do you mean I cannot just create it straight away like that? But I like it, it is easy and I know it well.

Well, the reason is simple once explained. This path will help you build a custom engine agent. But! The Sales agent needs a declarative agent for extensibility.

Lesson 2: You need to go to Microsoft 365 Copilot and create an agent

To extend the Sales agent, you can create sub-agents and connect them for specialized, custom skills. To do that, you must go within Copilot Studio in the Microsoft 365 Copilot area and then click +Add.

Mind blown? I know, me too when I first found out.

Lesson 3: How do I connect my new assistant agent?

Once you have built your assistant agent, you must go to the Sales agent in Copilot Studio, open it up, and go to Connected Agents to find it and add it.

Lesson 4: Help, I cannot find the newly created agent in Connected Agents!

Well, see Lesson 1. If you do not build a declarative agent, you will not see it in the Connected Agents list of agents to add. This is how you’ll know you have built the right type of agent for sure.

Lesson 5: Are there other ways to add these new skills?

Of course, ask and you shall receive! There are two pathways you can follow. Connected Agents is first up. But not the only one.

You can also click on Custom tools & knowledge.

How do I choose between Connected Agents and Custom tools & knowledge?

It is like asking what type of car you like driving. Both will get you to the destination, but they will operate differently and can cater to different audiences.

Explaining the key differences:

Visibility: If you want that transparent anatomy, then choose Connected Agents as they will show the sub-agents you have built. Hey, maybe this is a learning and adoption opportunity. However, if you want everything to appear under the single Sales agent entity, copy skills under Custom tools & knowledge.
Ownership, Control and Effort: With Connected Agents, someone else may own and evolve the skills. You can just consume their expertise, which involves way less operational effort in the process. Of course, you can still build and own It yourself too. Nevertheless, flexibility is helpful. With Custom tools & knowledge, you own the skills outright. As a result, you are also responsible for their full lifecycle. A governance point with clear boundaries to reflect on.
Updates and maintenance: Connected Agents automatically stay up to date when the owner improves their skills (yeay to no-sync headaches!). On the other hand, Custom tools & knowledge are point-in-time copies. This means that when something changes, you must update it yourself.
Availability: If there is one existing agent, then it is easy to just copy skills and use Custom tools & knowledge. But if you have multiple existing agents, then it is best you go to Connected Agents.
Compatibility: Depending on what features you are looking to extend the Sales agent with, you must look at compatibility. Certain features e.g., Adaptive Cards, are not supported by Connected Agents. This means you need to copy skills through Custom tools & knowledge instead.

The bigger picture for your architecture:

Choose:

Connected Agents when you want speed, leverage of existing agent assets, and minimal maintenance.
Custom tools & knowledge when you want unity, control, and full accountability.

It’s the difference between plugging into an existing agent ecosystem and building your own agent headquarters.

Bonus Lesson: Special content available to save you time!

There is already amazing content by the Microsoft FastTrack team and Amira Beldjilali. They recently published aka.ms/SalesExtensibility, a hands‑on, step‑by‑step guide to designing extensible sales experiences with Sales Agent in Microsoft 365 Copilot.

This may look familiar as it has been built like Sales Copilot Tip Time! You can find real scenarios, practical guidance, and a reusable format to adapt for your own scenarios.

Contents include step-by-step guides on: