A Job Description Describes the tasks and responsibilities of a particular position. It details what is expected of one who is fulfilling the job. The ninety-first Psalm has a brief but compelling job description for angels: "[God] shall give his angels charge over thee, to keep thee in all thy ways." Ps. 91:11.
Fulfilling this divine promise of heavenly care, angels, according to the Bible, gave assurance to a doubtful Abraham, guided a desperate Jacob, comforted a discouraged Elijah, and protected a threatened Daniel. In New Testament accounts, divine messengers announced the conception and birth of Jesus, ministered to him after the devil's temptations in the wilderness, guided Mary Magdalen from grief over Christ Jesus' crucifixion to the discernment of his resurrection, and led Peter to freedom from prison.
Guidance, protection, proclamation, ministering care, assurance of divine presence, comfort, encouragement, enlightenment— these are key elements of the job description for angels. It is an expansive but not exhaustive list, and not limited to Biblical times either. God's messengers still have charge over us, and take care of us in all our ways.