The "redistribute" command works for all IP routing protocol groups
The format of the command is documented here:
http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_pi/command/iri-cr-a1.html#GUID-9C67E447-FD2B-47E3-9A2C-334A41829A76
You have to identify the routing protocol (and AS, if applicable) that from which you intent to redistribute before adding any other arguments.
e.g.
redistribute rip (details)
redistribute eigrp 109 (details)
In your case, you omitted that and the command parser tried to interpret "metric" as if it were the name of a routing protocol.
"metric" is a valid argument (which is why the "help" works), but it needs to appear later in the multi-staged redistribute command.
Once could argue that Cisco should enhance the help to be more clever, but if you start with "redistribute ?" that step should be clear.
