When do we ask the user to try again on form input error?

I have a form whereby users are required to fill up several fields. Upon validation error, error messages would be shown. Example:

• The selected location is out of range. Please try again.
• The area does not match.
• The input should be in numerical format.
• Symbols are not allowed.

Somehow my gut feel tells me to use "Please try again" for the first error message but not the rest. Theoretically, I can use them everywhere. But they seem redundant at the same time. So, when should I ask the user to try again and when should I not? Is there any guideline I can follow?