Token to get a file uri?

I have the metatag → module installed, which provides an interface to specify values, including tokens, for outputting as <meta> tags on pages.

Is there a way to specify a token to get the URI (or any other property) of an arbitrary file that was uploaded to the site?

I'm hoping to be able to enter a token that may look like either of the following, where 12345 is a file's FID:

[file:12345:uri]
[file_entity:12345:uri]

Is that possible? And do you know if it's possible to get other file attributes for images like alt, title, width, height, etc?

For clarity... I don't want my token to depend on a file in a field on a node, but rather I want to just specify the FID for a file that could have been uploaded anywhere on the site. (And of course I would expect there to be an access check during file_load() or some such thing to make sure the file is viewable by the user/anonymous.)