Not necessarily. But you could easily add a few images with English descriptions next to them. That would be enough linguists to decipher the rest.

Just include a dictionary that is word-complete - i.e. does not contain any word or symbol that it doesn't also define.

All dictionaries are circular. Though it would be possible to learn the relationships between words, and perhaps decipher it that way.

Actually, not all dictionaries are circular - some are more definition-complete than others, and it does make a difference.

I mean circular, in that the definition's reference each other. E.g. if the definition for "happy" was "not sad" and the definition for "sad" was "not happy. If you didn't know one of those words already, the dictionary would be useless.