In what scenarios will this be useful to me?
How likely are these scenarios to come up?
If it does come up, will I remember I have this and be able to find it?
What other options will likely be available?
If I did get rid of this but realized I need another one, how difficult or expensive will it be to replace it?
Given how much space it takes and/or how much it will be in the way and the above responses, is it worth keeping? I'll also consider how much space I have, like if it takes up space in a toolbox where I still have space available, the "keep" option is a lot more likely than if I need to move things around each time I open it just to get it closed again.
(Once I've decided to get rid of it) How much value does it have to others?
Could anyone I know use it?
Would anyone I don't know want it?