조심성 있는 in English:

They became more circumspect, and that's what the X-men are.

Though I promised Marta’s father I would bring her home promptly by midnight, it would have been more circumspect not to have specified a time.

you should be more circumspect about making such allegations

To think carefully before doing or saying anything. In this day and age, you need to be circumspect about giving out too much personal information on the internet. The governor was usually circumspect when dealing with the media.

"If either of you is a Taurus, you must be circumspect in your financial dealings today."