I've setup a SQL srv 2000 and an Oracle 9i. I've linked them through OLE DB. When i fire the query:

select * from openquery(ORA, 'desc TABLE')

I get the following:

Server: Msg 7357, Level 16, State 2, Line 1
Could not process object 'desc TABLE'. The OLE DB provider 'MSDASQL' indicates that the object has no columns.
OLE DB error trace [Non-interface error: OLE DB provider unable to process object, since the object has no columnsProviderName='MSDASQL', Query=desc TABLE'].