The best way to determine a jazz chord is within the context of the previous/ proceeding chords and the key.

I saw this listed as a C13, sounds cool, but is missing a B for the Maj7 pitch

The Maj7th is missing because the C13 usually acts as a “dominant’ chord (in place of a dominant 7th; maj-min 7th chord).

Thanks for you comment!!

In theory, how is one to know the actual name for a chord when all these enharmonics are often used? For example, a Bb D E Ab is the Bb7b5 or it could an E7b5 in the 2nd inverion since the true notes are not used, but enharmonics are given. Darn confusing, isn’t it? Then in jazz they voice the chords so cool that sometimes it seems impossible to know for sure what the chord would be named, as example from lowest notes up: E A D G C F with 3 notes for each hand. I saw this listed as a C13, sounds cool, but is missing a B for the Maj7 pitch, so why not also call it an F9plus13 or since the D is not on top, an F9plus6 and in all cases, the inversion is not given, so lets just add the /E after the chords shall we? So now I read F9plus6/E. Crazy, music theory, stuff for those with too much time on their “hands”, haha!