This is no better description than the author's:
I personally use this and it does just what it says. It makes playing a straight or nearly straight mage slightly easier without over powering them and keeping things lore friendly. Though, after checking the mod page I realize I need to update because I'm currently using the older 1.3 which is modular. The newest (at the time of this writting) is 3.0 and it only includes one esp file.
This mod is intended to provide greater flexibility when playing as a mage. Instead of relying on a few overpowered gimmicks, mages should be able to experiment with different techniques in different situations, and still have a reasonable chance of overcoming their opponent. I have attempted to make each school of magic uniquely powerful while staying pure to Elder Scrolls lore; these were the considerations I made when addressing each school of magic:
Alteration is the school of magic which deals with altering the physical world. Alteration mages can bend the laws of nature, changing the world around them. Many alteration spells are utilitarian - they allow the caster to access hard to reach areas, to lighten a burden, to breathe water as though it were air, etc., but alteration also has a place in combat. Alteration mages can change the composition of their own bodies, making them less susceptible to certain types of damage, or exhaust an opponent by making their own weapons and armor much heavier to carry.
Conjuration mages are able to telepathically commune with Daedra and the undead, and bend them to their will – for a time, at least. As the conjuror becomes more skilled, he may control more powerful servants for a greater length of time. Conjuration mages may also call forth mighty weapons from Oblivion, or bind the souls of the slain.
Destruction mages wield the destructive force of the elements to wreak havoc in battle. Their magic can ignore armor or take out an entire room full of enemies. With a full arsenal of spells at their command, there are few who can stand against a powerful destruction mage.
With the power to manipulate the mind, mages who study the school of Illusion can change what one perceives – for good or ill. While not able to deal much damage directly, a single Illusionist can turn the tide of a battle, causing enemies to fight amongst themselves or giving allies the confidence to surge forward. A skilled Illusionist is subtle, veiled in silence and cloaked in invisibility, often undetected by those she manipulates.
Those who practice restoration are not only excellent healers, they can also channel the powers of magicka to protect, strengthen, and enhance. Many restoration mages choose to serve as priests and healers, and are welcomed even by those who are generally suspicious of magic users. Their powerful bond to life causes undead to recoil in fear.
Enchanters, while not exactly spellcasters, are nevertheless intrigued by the magical arts, and are able to imbue physical objects with magical properties. Masters of enchantment can turn quality equipment into powerful artifacts, nearly as great as those of legend.