In the automation agent's cluster configuration (http://mms.mongodb.com/help/reference/automation-agent/), both monitoringVersions and backupVersions both now take an optional "logRotate" key which points to an object:

"logRotate" : <obj> // spec to rotate the logs for an agent

{ "sizeThresholdMB" : <number> // (required) max size in MB for an individual log file before rotation "timeThresholdHrs" : <int> // (required) max time in hours for an individual log file before rotation "numUncompressed": <int> // (optional) max number of total log files to leave uncompressed (including current log file) // default : 5 "percentOfDiskspace" : <number> // (optional) max percent of total disk space all log files should take up before deletion // default : .02 }