At present we have "--verbose" option for mongo shell - with that additional diagnostic messages are printed. However the verbosity level still does not match those we can have with the drivers.

For example we can get this sort of debug messages from the Ruby driver:

D, [2016-10-26T17:39:21.344620 #5949] DEBUG -- : MONGODB | mubuntu:27017 | test.delete | STARTED | {"delete"=>"testcol", "deletes"=>[{"q"=>{}, "limit"=>0}], "ordered"=>true}
D, [2016-10-26T17:39:21.834861 #5949] DEBUG -- : MONGODB | mubuntu:27017 | test.delete | SUCCEEDED | 0.490105045s

It would be nice to have a proper DEBUG mode for the shell that would provide similar level of logging.