It depends on the Options of the 3rd Party tools. If they can display the current logchain.
I don't know any db2 command to see the current logchain. DB2 writes an entry in db2diag.log for each archived logfile. Maybe you can parse the db2diag.log. We are using TSM and the entries have the eduid 5772.
> db2diag -eduid 5772
2010-01-19-07.11.04.328000+060 I11713613F439 LEVEL: Warning
PID : 820 TID : 5772 PROC : db2syscs.exe
INSTANCE: DB2 NODE : 000
EDUID : 5772 EDUNAME: db2logmgr (DBNAME)
FUNCTION: DB2 UDB, data protection services, sqlpgArchiveLogFile, probe:3180
MESSAGE : Completed archive for log file S0000544.LOG to TSM chain 1 from