For FILE_TRIGGER jobs you can use additional criteria depending on the type. Using the CREATE parameter, you can also use the NOCHANGE(xxxxxxx) keyword, which instruct the agent to satisfy the file trigger only after the file has remained unchanged for the amount of minutes specified.
For example:
FILENAME C:\TEST\test1.txt CREATE NOCHANGE(2)
The example of above will cause the agent to detect the creation of the file and then wait for the file to remain unchanged for 2 minutes.
Below is a link to the documentation that talk about the FILENAME statement:
https://techdocs.broadcom.com/us/en/ca-mainframe-software/automation/ca-workload-automation-ca-7-edition/12-1/related-documentation/use-ca-ias/c-lang-statements/filename-statement-specify-file-to-monitor.html