Copilot Studio Agent vs SharePoint subfolders

Copilot Studio does not reliably index or retrieve content when a subfolder is added on its own. In contrast, full sites and full document libraries index and respond correctly.

Although SharePoint agents support folders as knowledge sources, Copilot Studio and SharePoint agents still use different ingestion models. The SharePoint FAQ confirms that integration with Copilot Studio is still in progress and that the two systems do not yet share complete indexing behavior. 

Why This Happens

Copilot Studio depends on the SharePoint search index, which consistently provides full-site and full-library indexing but does not reliably produce complete index payloads for isolated subfolders. As a result, Copilot Studio cannot find documents even though they are accessible to the user and visible in the SharePoint UI.

There is no published Microsoft documentation that indicates this limitation has been resolved as of 2026. The ingestion model remains unchanged.

Recommended Workarounds

To ensure content is discoverable:

1. Add the entire document library as the knowledge source.
2. Create a dedicated, smaller library if you need tighter scoping.
3. Add individual files when necessary (up to supported limits).

Conclusion

This behavior is expected given the current product architecture. Subfolders alone are not reliably indexed by Copilot Studio agents, and Microsoft has not yet documented support for this configuration. The recommended approach is to use libraries, sites, or individually selected files until deeper SharePoint–Copilot Studio integration is completed.