Scott, I agree with you that it could do a better job of providing context as it gives almost none at all. Occasionally I'll cut and paste something more descriptive, but that's just a stopgap. I've noted similar things in the past: https://github.com/kylewm/KnownReactions/issues/14

A possibly better version might be a mashup of Known's "Share" funcitonality, but with the proper markup for likes and reposts, but this would take a bit of reconfiguration which I haven't had the itch to fix just yet. My general value on likes and reposts like these is fairly low and if I want to keep more context I use other methods, particularly if I want to keep more context for my personal site search in the future.

In particular, for things like these, I'm a big fan of having the actual blockquote of tweets using their javascript for display, that way if Twitter were to fail one day, I'll still have the physical content even if I loose the display portion.