SQLAgent Properties

To view its properties, use 

EXEC msdb..sp_get_sqlagent_properties

To set a SQLAgent property, use

EXEC msdb.dbo.sp_set_sqlagent_propertie @property=''

An example can be changing SQLAgent's log file directory:

EXEC msdb.dbo.sp_set_sqlagent_properties 

@errorlog_file=N'a dir\SQLAGENT.OUT'