Just to expand on this, running these missions will only raise Agent and Corporation standing. Most of the required items are random drops found in Cosmos Complexes which takes a long time to collect. If you buy the items from the Market, it will cost you more than what the mission reward pays.
Here’s some examples of why the single mission Cosmos Agents are not worth the time to do.
Taru Kubona = Level 1 Caldari Cosmos Agent - Otitoh System - Devil’s Dig Site
Mission = Finders Keepers
Objective = Acquire 4 units of Talocan Mechanical Gears (4.0m³)
Reward = 45,000 ISK ; Bonus 20.000 ISK (completed within 60 minutes)
Average Market price for that item is about 100,000 ISK.
Another example:
Abotur Kverkinn = Level 2 Minmatar Cosmos Agent - Hjoramold System - Lord Bastion
Mission = Too Good to be True
Objective = Acquire 2 units of Sleeper Nanite Cluster (2.0m³)
Reward = 45,000 ISK ; Bonus: 20,000 ISK (completed within 60 minutes)
Average Market price for that item is about 200,000 ISK.
Another example:
Akraun Maertigor = Level 2 Minmatar Cosmos Agent - Barkrik System - The Hyperbole Nexus
Mission = The Lullaby
Objective = Acquire 4 units of Sleeper Data Crystals (4.0m³)
Reward = 45,000 ISK ; Bonus: 20,000 ISK (completed within 60 minutes)
Average Market Price for that item is 500,000 ISK.