"Even I had forgotten that the sword was forged in purity and strength. It can only be used for good. In the hand of evil, it can never harm an innocent."
— Jack, Samurai Jack episode "Jack and the Zombies"
If you want an inanimate object shining on a pedestal with choir accompaniment, inspiring awe in The Hero with its holy magnificence, the Evil Overlord recoiling in terror for fear of his very life, then you want an Artifact of Hope. This thing cleanses, disinfects, blesses, beautifies, purifies, protects, heals, brings joy to children and smells like fresh coffee.
Only the Pure of Heart may wield these mighty trinkets, or at least they weren't meant to be used by anyone else. If the wielder is anything other than The Paragon with a soul of The Incorruptible, at best the Artifact will fail in their hands. At worst, they'll drop the thing with fresh burn marks scarring their hands. This makes it especially awkward when the Big Bad had gone through so much to procure the object themselves — taking every moral shortcut and stabbing so many backs to get to it — only for the thing to break itself the second they get their hands on it.
These things are usually Situational Swords, the wielder only able to use the artifact to their fullest potential when it's absolutely needed. Or when you need more dramatic tension. Or when the hero needs to learn that they had the power within them all along and they don't need a Sword of Plot Advancement to save the universe. Expect them to need The Power of Love, The Power of Family, The Power of Friendship, The Power of Trust, The Power of Rock or Virgin Power to operate.
Sealed Evil in a Can can qualify as an example, specifically because the artifact was created to keep the evil imprisoned. If it's a Sealed Good in a Can, then the artifact was created to unleash a Big Good of some kind when certain conditions are met.
If sentient, expect the artifact to exude an aura of wisdom and prudence, giving The Hero helpful, if-not cryptic, advice.
The Evil Counterpart of the Artifact of Hope is the Artifact of Doom, an Always Chaotic Evil artifact that can only be wielded by evil, can only be used for evil or most certainly turns its wielder evil. Since there is a balance between good and evil, expect them to be Counterpart Artifacts and/or Nemesis Weapons to one another.
Compare Embodiment of Virtue, Holy Hand Grenade and Holy Is Not Safe.