In general, it would be easier to use – and, importantly, to learn – the shell if all shell commands worked in a similar way, and could be used in the same way from a hand-typed JavaScript or a file-based JavaScript. In particular, all commands that retrieve some data should return that data as a well-formed BSON object. Since the shell already echoes return values to the shell, there should be no usability harm in doing things this way. I see the following culprits:

• db.printCollectionStats
• db.printReplicationInfo
• db.printShardingStatus
• db.printSlaveReplicationInfo