Basically, any in-game number that can be listed as a percentage needs to be outright stated to the player. For example, Rampage, Kill Clip, Frenzy, Swashbuckler, and One For All, are all perks that "provide increased damage for a short duration", they all use the exact same wording yet provide substantially different effects. There's no way to know that One For All gives a larger damage bonus than Frenzy without the player being given that information from an outside source. This effect is also the case for most effects in the game. "Grants a small amount of ability energy", "Increases reload speed", and "Improved chance for an exotic" are also near ubiquitous phrases that actually provide little to no information on how much it actually helps you. Obviously it can't be shown in the short description of a perk, but there needs to be a way to inspect a perk or phrase and be shown the actual percent or numbered benefits you get. That sort of character and gear information should be visible in the game, and not require a player to watch a YouTube video breakdown of damage testing every perk that comes out.