The game has an element of mystery/discovery to it. If it was me, I would make kra only partially knowledgeable about the effects of these items - leaving a little room for surprise. This also gives kra room for growth over time.
As a rule of thumb, lower delay makes a weapon hit more times per second. This has great effect on damage over a period of time. Other modifiers are pretty obvious..
Its always been hard to tell how good an item is given its name. Some are duds, others give buffs or debuffs. Debuffs can be desirable too for training.
You could also have kra ask others what they know about various items... their history perhaps, or about their experience with them. You may get some misinformation or bullshit, but that's ok too. Not knowing and misunderstanding are a part of life and life's journey.