What is "TALagent" and why is it "Exiting out of boredom"?
It's not a virus and it's not a customer facing tool since it uses the terminal. Sometimes command line tools don't even get a manual page - so this is one of the much better documented tools.

The Transparent Application Lifestyle is fancy words for versions and auto-save. If you open TextEdit and make a document, you never have to save your work or choose where the untitled document is stored. TAL saves it and then assists with versioning once you explicitly save the document to the filesystem or cloud.

If you're not convinced it ships from Apple, use mdfind talagent to examine where the tool is installed.

Apple runs it at 3 am on Mondays and Thursdays on your Mac by default, so there's not much mystery that it runs and then exits as opposed to something that runs forever waiting for work to do.

It's nice to double check since governments are now clearly equipped to suppress knowledge of their state sponsored malware by using legal threats and gag orders. I'd say some healthy skepticism is in order when you see something not right on your computer.