D&D 5E Repeating information for easier reference VS Shared description to save space

[GX.Sigma]

For most things: Just put it in both places.

For spells: I can remember what spells do. I know that fireball explodes, I know that cloudkill kills people with a cloud. Just put a few numbers (the DC, the damage) so I don't have to look it up unless something weird happens.

 

[delericho]

But I am otherwise not convinced about reprinting every monster in an adventure... someone who buys a lot of adventures could soon buy an extra MM with the money saved from not reprinting monsters, and then cut the pages into "cards".

In all honesty, I don't expect 5e to have many in-print adventures - certainly fewer than even 4e had. I would expect the majority of adventure support to come in the form of eDungeon adventures and (possibly) PDFs. In either of those two cases, there really isn't a lot of reason not to reprint the monsters, given that it's just a cut-and-paste job.