Agent is the easiest of the 3 difficulty settings in both GoldenEye 007 and Perfect Dark. Enemies are inaccurate and cause less damage than in the higher difficulties. Body Armor is abundant and easily accessible. Players also have fewer objectives to complete. In Perfect Dark, players must complete 3 objectives in normal missions and 1 in special missions, whereas the number of objectives varies in Goldeneye. The higher difficulties are Secret Agent and 00 Agent in Goldeneye and Special Agent and Perfect Agent in Perfect Dark.
Practically speaking, this means the main focus when playing for speed times on Agent difficulty is on speed and accuracy of strafing, and general technique with buttons and gadgets and so on. Combat with the enemy is basically optional; enemies are only killed if they ARE critical mission objectives or they obstruct critical mission objectives (i.e. it would be slower to leave them alive).