I have a nuget package that is built with XML documentation file enabled and included in the build and pack. The XML file shows both in the build output directory and in the downloaded package directory next to the DLL file with the same filename.
When the package is imported in another solution via nuget.org the summaries do not show at all.
I have also read this thread and added the following to my .csproj file:
<None Include="pathtoxml\xmlname.xml" Pack="true"><PackageCopyToOutput>true</PackageCopyToOutput></None>