following this post i commented the lines and now the result is different.
[root@SRV-ORACLE ~]# /usr/lib/check_mk_agent/plugins/mk_oracle -t
<<<oracle_instance>>>
<<<oracle_sessions>>>
<<<oracle_logswitches>>>
<<<oracle_undostat>>>
<<<oracle_recovery_area>>>
<<<oracle_processes>>>
<<<oracle_recovery_status>>>
<<<oracle_longactivesessions>>>
<<<oracle_dataguard_stats>>>
<<<oracle_performance>>>
<<<oracle_locks>>>
<<<oracle_systemparameter>>>
<<<oracle_tablespaces>>>
<<<oracle_rman>>>
<<<oracle_jobs>>>
<<<oracle_resumable>>>
<<<oracle_iostats>>>
<<<oracle_instance>>>
<<<oracle_processes>>>
<<<oracle_asm_diskgroup>>>
---login----------------------------------------------------------------
Operating System: Linux
ORACLE_HOME (oratab): /oracle/product/10.2.0/db_1
Logincheck to Instance: ORASII
Version: 10.2
Logindetails: checkmk/XXXXXXX@(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521))(CONNECT_DATA=(SID=ORASII)(SERVER=DEDICATED)(UR=A)))
Error Message: ORASII|FAILURE|ERROR: ORA-12541: TNS:no listener SP2-0751: Unable to connect to Oracle. Exiting S
SYNC_SECTIONS: instance sessions logswitches undostat recovery_area processes recovery_status longactivesessions dataguard_stats performance locks systemparameter
ASYNC_SECTIONS: tablespaces rman jobs resumable iostats
------------------------------------------------------------------------