The admin user works but is quite risky to have all permissions on a database for just monitoring purposes. You also won’t giva any user SAP_ALL to your systems 
With the parameters you wrote it’s possible to monitor a lot of functions of the HANA database, all you need is a user with the MONITORING role. You can provide the credentials at the rule directly or let your DBA add it to the hdbuserstore so you never have the password clear text anywhere.
The following services are monitored:
SAP HANA Backup <SID> <INSTANCENR> - complete data backup
SAP HANA Backup <SID> <INSTANCENR> - log backup
SAP HANA Disk <SID> <INSTANCENR> - Data
SAP HANA Disk <SID> <INSTANCENR> - Log
SAP HANA Disk <SID> <INSTANCENR> - Trace
SAP HANA Events <SID> <INSTANCENR>
SAP HANA License <SID> <INSTANCENR>
SAP HANA Replication Status
SAP HANA Status <SID> <INSTANCENR>
SAP HANA Version <SID> <INSTANCENR>
The HANA monitoring from SAP is okay, but doesn’t provide the best informations yet. Additional you will get some trouble to well configure the HANA system inside LMDB, because SLD doesn’t provide all informations needed at the moment. The checkmk plugin also provide this information state based and the Solution Manager only works event based. And you are also depending on the administrators of solution manager to patch all the modules to have the latest monitoring available from SAP.
Also the initial configuration to run the monitoring via Solution Manager is huge, you have to have diagnostic agents on each host, have configured the database monitoring connection inside the SAP system, have to run the Managed System Configuration inside Solution Manager for this system, have to enable the MAI, configure the MAI for your thresholds and i am sure, I missed some steps so far. Therefor it’s much easier for the beginning to just install a checkmk agent on the host and create a database user with the right role.
And all in all you will also get some free help around for the check plugin and don’t have to pay a SAP consultant. 