The tools headers include options to connect to a server and some other things (like specifying a collection to work with) which are not appropriate to this tool. This program should probably get its own explicit args listed for "--help" and a better description listed about json/debug output.

$ ./bsondump --help
usage: .\bsondump.exe [options] <bson filename>
options:
--help produce help message
-v [ --verbose ] be more verbose (include multiple times for more
verbosity e.g. -vvvvv)
-h [ --host ] arg mongo host to connect to ("left,right" for pairs)
--port arg server port. Can also use --host hostname:port
-d [ --db ] arg database to use
-c [ --collection ] arg collection to use (some commands)
-u [ --username ] arg username
-p [ --password ] arg password
--ipv6 enable IPv6 support (disabled by default)
--dbpath arg directly access mongod database files in the given
path, instead of connecting to a mongod server -
needs to lock the data directory, so cannot be used
if a mongod is currently accessing the same path
--directoryperdb if dbpath specified, each db is in a separate
directory
--objcheck validate object before inserting
--filter arg filter to apply before inserting
--type arg (=json) type of output: json,debug