Which is Preferred: sys.argv or arcpy.GetParameterAsText in Accessing Geoprocessing Tool Parameters

One of my clients asked me to run the script geoprocessing tool, I developed for him, from Command Prompt. The tool has nine parameters and it is contained in a custom ArcGIS Toolbox. It is intended to be run inside ArcMap. I finished developing the tool and running it perfectly as any other built-in tool.

At the beginning, I thought it needs little modifications to run it from command prompt. In particular, I thought I need to get the parameter values through sys.argv as I am used to do for Python scripts, intended to be run from command prompt. what was surprising, It doesn't need any modification to do that.

The function arcpy.GetParameterAsText works as if you would use sys.argv to access the parameters. According to ArcGIS Help Documentation, Arcpy.GetParameterAsText is preferred since it has no character limit, while sys.argv has limitations on the number of characters it can accept.

The illustration below shows a script tool dialog box with three parameters.