new feature request: error report if you use an underscore instead of a colon

when trying to run dosdp tools, I accidentally used an underscore in an ID instead of a colon. Would be nice to have a way to easily identify this error.

Start by reproducing a dosdp tools invocation that uses an underscore in an ID, then trace where IDs are parsed and errors are reported. Review the surrounding command-line handling to determine the intended diagnostic, and consider the work complete when the mistake produces a clear, actionable error.

Written by the indexing model from the issue text.