aws –profile=joox-elbs ec2 describe-instances –instance-ids={“i-242efb14″,”i-2a1736d2″}

However, I believe this invocation will return instances with a tag called “Name” regardless of the tag value:

aws ec2 describe-instances --filter "Name=instance-state-name,Values=running" "Name=tag-key,Values=Name" "Name=tag-value,Values=''"

From the docs:

> tag-key – The key of a tag assigned to the resource. This filter is independent of the tag-value filter. For example, if you use both the filter “tag-key=Purpose” and the filter “tag-value=X”, you get any resources assigned both the tag key Purpose (regardless of what the tag’s value is), and the tag value X (regardless of what the tag’s key is). If you want to list only resources where Purpose is X, see the tag :key =*value* filter.

You should use:

aws ec2 describe-instances --filter "Name=instance-state-name,Values=running" "Name=tag:Name,Values=''"