Condition is evaluated as True, only when IssueManager evaluate Issue Workflow condition.
It is the way used to restrict the Edit Action Workflow Action to be available only for Edit Operation.
When defined, there is no special configuration.
The Condition configuration may be done in XML in Workflow descriptor as follow :
<condition type="class"> <arg name="class.name">com.atlassian.jira.workflow.condition.ValidatingIssueCondition</arg> </condition>