Notes About Agility:
The main point of the Agility stat is to balance out the Speed and Strength stats (much like the Endurance stat). Because of this, the Agility stat is not designed to give your character buffs, but instead it is designed to give your character the ability to unlock its potential as this stat is increased. Agility is difficult to gauge on a number scale, so instead will be a list of general descriptions of what your character will be capable of at each amount, along with little bonuses they get at each tier.
The Chart
5 - Basic Agility, you have the capabilities of a normal, fit adult. Nothing extreme, but not bad.
10 - Honed Agility, you are a trained warrior and your movements are sculpted to echo as such. More difficult dodges and maneuvers can be performed, but again nothing too extreme. (Ex: Sweep kicks, somersaults, jump dodges)
15 - Advanced Agility, you are a careful and capable professional. You are capable of performing risky tricks and maneuvers as well as basic parkour. You know how to shift your weight to fit your intentions, and your steps are now silent unless wearing heavy armor (be realistic on that one). (Ex: Back/front flips, vaulting, tucking & rolling)
20 - Catlike Agility, you clearly needed to train agility to match your class or profession, and your skills show the training that you've been through. You are now capable of climbing up ropes and pipes with ease, as well as climbing up building and mountains as long as there's the slightest things to grab. Your jump height is now twice as large (normal jump height being half your body size, this being your full height). You are lean and fit, barely showing any body fat.
30 - Extreme Agility, this is more of an extension of the last tier. You can now walk completely silently no matter what you are wearing, you can climb completely flat surfaces with ease.
40 - Extreme Agility Pt. 2, you receive no fall damage whatsoever, as you have perfected rolling on landings from jumping off of high places. The height does not matter.
50 - Master Agility, your stance cannot be hindered. After taking a hit that would likewise knock you down, you simply land perfectly on your feet and in position once more. It looks inhuman and unnatural, and no one can quite explain how you do it unless they can do it themselves.