Hello,
the default logging level for log-tmsagentproxy is WARN. You could turn it off altogether, check page 320 of the attached user guide for instructions.
Since log-tmsagentproxy logs the activity of the Cisco TMSPE IIS Proxy, the following applies. What it comes down to is that you have to purge these logs in IIS:
IIS logs
Cisco TMS uses Windows Server’s Internet Information Services (IIS) as its web server. The IIS logs could be useful for troubleshooting certain kinds of Cisco TMS problems, for example:
n CDR data is missing.
n Intermittent phone book problems.
n The Cisco TMS web interface loads very slowly.
In default IIS installations, the logs are found in the C:\inetpub\logs\LogFiles folder. When correlating IIS log entries with Cisco TMS log entries, note that IIS log entries are in UTC.
For assistance on configuring the IIS logs, see the following Microsoft TechNet article:
http://technet.microsoft.com/en-us/library/cc732079%28v=ws.10%29.aspx
Purging IIS logs
Note that IIS logs are not part of the Cisco TMS purge log plan. We recommend setting up your own purge plan or manually removing these logs at regular intervals.
https://www.cisco.com/c/dam/en/us/td/docs/telepresence/infrastructure/tms/admin_guide/Cisco-TMS-Admin-Guide-14-6.pdf