When designing a script, you more than likely will create some errors. The Script Tool engine has the ability to detect most syntax oriented errors and report them to you before your script is executed.
When an error is detected, the Script Tool engine will give a message similar to the following:
In the example above, the dialog box show the code that caused the error (the software name and macro name), the error number, the line (in your script) the error occurred in, and then a complete description about the error.
You can use this information to narrow down the location and cause of errors in your scripts.
Note that this will not catch logic errors (you meant True instead of False), but only syntax errors in the language.
Please refer to the Visual Basic scripting lists on Syntax and Runtime errors.