The lore book vol. 1 and vol. 2 has descriptions of 2 or 3 abilities for each job, as well as their LB3. I wish there were more, as it adds more depth to the job, especially for RPing. Here is my head-canon descriptions of the Lancer and its skills.
Lancer: A fighter trained in the art of the spear and lance. Unlike other types of warriors that rely on brute strength, a lancer uses speed, timing, and swift blows to unbalance their foes and exploit weak points with deadly accuracy.
Heavy Thrust: Similar to how a pugilist or boxer uses a jab to "measure" the distance of their target and keep them in range of their fist and foot, a Lancer uses this simple thrust-and-slash combination to measure the optimal striking range for subsequent flurries to reduce the chance of glancing strikes.
True Thrust: The lancer learns that by stepping forward in combination with spinning their polearm, adds more weight as well as centripetal force to their thrust, increasing its penetrative ability and causing deeper wounds than a standard thrust.
Vorpal Thrust:A swift and painful horizontal swing to the side of the opponent knocks the opponent off balance just long enough to be skewered by an unsuspecting follow-up rushing thrust.
Full Thrust: A Lancer spares not a modicum of energy on superfluous movement, and while seemingly a garish flourish, the Full Thrust technique is neither. After staggering an opponent off-balance with Vorpal Thrust, the Lancer, without skipping a beat drops their weight suddenly and springs up in an explosive rising uppercut. This finishing strike brings to bear the full weight of their body, armor, and haft, focalized into the tip of their weapon. The inertia and momentum of this technique either sends the target hurdling onto their back, or splits them in twain from loin to temple.
Piercing Talon: Spears and lances make for excellent missiles when thrown, and can pierce armor or stagger targets from a distance before they even get within range of counter-attacks. Lancers learn early on in their training however, that throws are optimal from long distances and is not something to be used at close-range where more targetted strikes are optimal.
Life Surge: The Lancer rouses their internal aether to achieve a sudden and temporary surge of speed, allowing them to deliver an especially square attack, timed perfectly during an opening in the enemy's defense. As any fighter knows, delivering such a well-timed critical strike can renew one's moral, gaining a second-wind.
Blood for Blood: Normally a Lancer returns to an on-guard position after measured flurries, always being wary of counter-attacks. However, the Lancer can forgo the orthodox balanced stance in favor of a more aggressive approach to make short work of the target. Doing so is normally risky in singular combat unless making sport of a weaker target that is of little threat, but lancers rarely fight alone. While the opponent is distracted fighting an ally, the Lancer is not want for defense, and can focus solely on targetting vitals and gaps in armor. However, being struck while off-guard can be especially dangerous for a lightly armored combatant such as a Lancer.
Impulse Drive: The lancer's thrusts are useless against a guarded-foe, so he delivers an unsuspecting uppercut, knocking away the target's guard from below, leaving their upper regions primed for a deadly overhead-thrust, followed by a deep thrust to the chest.
Disembowel: The lancer delivers an upward angled strike to the head of the target, causing the opponent to guard high, followed by a crushing lateral swing to the upper torso, causing their opponent's shield or defenses to be jarred. In this split second of defenselessness, the lancer then delivers a deceptive thrust from under their arm to the belly of the target adding the centripetal force of a quick spin to punch armor plate or crush carapace.
Chaos Thrust:Having skewered, split, and pierced the defenses of the target using Impulse Drive and Disembowel, the defenseless target is utterly helpless. The lancer makes sport of the target by tearing through flesh and bone with two puissant swings, opening up two wide gashes. As the target reels in agony, the Lancer spins his polearm and delivers an eviscerating thrust that if not absolutely exsanguinates the foe, saps their strength and will to fight. The blood splatters caused by this graceful and deft combination are oft compared to a flurry of cherry blossom petals, a poetic symbol of the brevity of life, blowing in a spring's breeze.
If you like this, maybe I'll cover Dragoon's as well since there's more lore involved with their attacks, and maybe I'll do some other jobs I like to play as well.