Forum Discussion

ahaggin's avatar
ahaggin
Copper Contributor
Aug 07, 2026

Snippet Files Truncating Data - Excel

Dear community, 

 

Background

I am looking for feedback regarding a best practice for using Microsoft Excel files as a knowledge source. My data is structured in a tabular format, stored across 3-4 columns in Excel (~500 rows, one sheet). For context, it is a simple mapping file that can be used to query about team responsibilities and who to contact for a specific topic/region/etc. I use this file in parallel with Outlook and Teams tools to escalate topics directly to individuals. I have a skill already created (contacts-responsibilities) that very clearly details the file and how the Agent should behave. 

Issue

In the "developer" preview, I can see the Agent is identifying the correct knowledge source, but the processing technique is resulting in truncated snippet files. After multiple fail-retry loops, the Agent concludes that the data is not present in the file (which it most certainly is). Here are some of the notes the Agent returns: 

  • "the snippet seems to be limited to a certain portion of the file"
  • "the search result only returned partial data from the spreadsheet."

Ask

Any suggestions on what exactly to do here? I have read that issues should only occur when you hit 1500+ rows of data. I could split my data apart, but this would mean more maintenance on my side. Thank you! Any hint is appreciated. 

 

 

Agent Builder
copilot studio

1 Reply

  • CoralieSimonaire's avatar
    CoralieSimonaire
    Brass Contributor
    Aug 09, 2026

    Hi,

    The agent does not read Excel files linearly. It retrieves chunks of content via a search mechanism, and the chunk size cannot be configured. This is consistent with what the community reports, though Microsoft has not formally documented the exact chunking limits for this experience.

    That agents respond best to Excel data when it is on a single sheet within a workbook, which seems to be your case already. However, for tabular lookup data specifically, a SharePoint List tends to be a better fit as a knowledge source, with documented support for up to 20,000 rows and 50 MB of raw text.

    That said, I want to be transparent : I do not have official Microsoft documentation confirming the 1,500-row threshold you mentioned, and the behavior may also vary depending on whether you are using Agent Builder or Copilot Studio directly. It would be worth clarifying which exact experience you are working in, as the knowledge source handling differs between the two.

    The SharePoint List approach is the option I would suggest exploring first, before splitting your file.

    Hope this helps