vbuckettool help/usage needs improvement

key WRONG_KEY doesn't exist in bucket

[root@cen-2708 tools]# curl http://localhost:8091/pools/default/buckets/default | ./vbuckettool - WRONG_KEY
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 9837 100 9837 0 0 12047 0 -::- -::- -::- 1601k
key: WRONG_KEY master: 10.3.121.66:11210 vBucketId: 739 couchApiBase: http://10.3.121.66:8092/default replicas: 10.3.121.63:11210

description:

./vbuckettool
vbuckettool mapfile key0 [key1 ... [keyN]]

The vbuckettool expects a vBucketServerMap JSON mapfile, and
will print the vBucketId and servers each key should live on.
You may use '-' instead for the filename to specify stdin.

Examples:
./vbuckettool file.json some_key another_key

curl http://HOST:8091/pools/default/buckets/default | \
./vbuckettool - some_key another_key