Create a manual check (WATO → Manual Checks) for State and count of processes. Choose some conditions (like hostname, folder, or tags) and set the following attributes:
With these levels the check goes to the warning state if more than zero processes with the name /bin/sleep exists. Change that name to the name of your process, e.g. /bin/ds_agent (or whatever path makes sense).
But please be aware that the check will only go WARN if the process runs at the very moment the check_mk_agent queries the process list. I don’t know about ds_agent but if it usually runs for just a few seconds once in a while then you won’t benefit from this check.