Social skills are the behaviors used to manage relationships. We use social skills to participate in, and react to, social interactions. Key factors include shyness, expressivity, sensitivity, control, accurate appraisal, and how people perceive behaviors.
Instruments like the Chapin Social Insight Test and Social Skills Inventory measure social perceptiveness and competence. Other instruments, like those in the Social Climate Scales, measure social behaviors within a specific environment (eg. family, work, school) to address that environments can impact the social skills one uses or is perceived to use.