Unexpected 429 Errors from SharePoint /list and /content APIs – Not Near Documented Limits

Hi everyone,

I'm currently working with the Microsoft Graph /list API to retrieve files from a SharePoint document library and then using the /content endpoint to download each file.

After processing approximately 1000 records, I began receiving 429 Too Many Requests errors. On reviewing the API traffic from my application, I found that we're only making about 150 API calls per minute, which is well below the documented thresholds.

According to Microsoft’s guidance on avoiding throttling in SharePoint Online (link to docs), the usage is nowhere near the stated API or egress limits — especially the tenant-level thresholds like 1,200 API calls/min or 100GB/hour egress.

What’s puzzling is the lack of transparency — I’m unable to find any dashboards, logs, or reports in Microsoft 365 or Entra that show how many API requests are being made or what limits are being approached.

My questions:

• Are there any hidden or undocumented limits (e.g., per-user, per-app, or per-site collection)?
• Could /content downloads have higher cost per call or impact the limit differently?
• Is there any way to monitor detailed API usage against SharePoint or Graph API from the Microsoft portal?

Would appreciate any guidance or insights from others who’ve faced similar issues!

Thanks in advance!