-It would be great if in the description of this field, "filemd5" could link to this page: http://docs.mongodb.org/manual/reference/command/filemd5/
-This could possibly say "filemd5 command" instead of "filemd5 API," since it really is just one command.
-It would be great to explain here where this md5 hash comes from (it is computed based on all of the data in the file, pulled from each matching chunk in the 'chunks' collection sequentially). I'm not sure if this information was omitted on purpose, for some reason, but it would have been helpful to me to find it here. Since it seems as though this page is meant as a spec for gridfs implementors, it seems natural to include this information here.