CSOM batch request: “Request uses too many resources” when loading multiple sites with GetSiteByUrl

I’m currently exploring CSOM (Client-Side Object Model) and analyzing how property values for client objects such as Web and Site are requested and returned in XML format. I used Fiddler to inspect the request and response bodies.

I’m now trying to implement a batch-based query where I load multiple sites with a limited set of properties using the GetSiteByUrl method.

However, I’m running into this issue:

• When I load 10 sites, I get the error:
• “Request uses too many resources.”
• When I reduce the number to 8 sites, it works fine.

I also compared the bytes sent and bytes received for different batch sizes (screenshot attached).

So my question is:
Is there a specific limitation on the total request size (bytes sent/received) or number of operations in a single CSOM batch request?
If yes, is there any official documentation or guidance on how to determine these limits?

Thanks in advance!