There are different views on this subject. Some jazz lead sheets just use basic chords such as a V7 and leave the player to select the extensions such as V9, V13, V alt, V7b9 etc.
I believe that the selection of the chord should be in harmony with the melody although in jazz, a reharmonization can be done that actually changes the tune (ex: Over the Rainbow
by Dave Brubeck).

Passing notes are generally not necessary to harmonize unless a specific pattern in the accompaniment is important to the arranger such as the C/C, C/B, C/A, C/G, shown above.
The selection of the bass note in the chord may or may not be important.

If you are dealing with a three-chord I,IV,V7 progression, I see no need to include a
harmony for a passing tone.