Not sure what you were aiming for, with
Always put the placement as the first parameter, such as
Note that while 'File:' isn't wrong, I prefer 'Image' as it is more accurate. It's actually possible to embed other types of file.
Unless there is a very good reason, keep your images to a maximum of 500px - the 'thumb' parameter means they can look at the original. We use 350px as the standard for images where you don't need to read fine print. That keeps a consistent look, but you can use larger sizes where there is sufficient reason.