Greater Granularity In Snmp Traps

Currently the KB article about SNMP traps really (unless i’m misreading or looking at an old version) provides a rather “blunt instrument” for external checks resulting only in Critical warnings and not much for recovery.  Is there more documentaion on setting warns or recoverys based on SNMP?  There was another note about requsting more documentation on external checks is there more detailed information or examples on how to best put this together?  Is more “directly” handling of SNMP traps on the horizion for features?