What this does: If you're tired of unruly toddlers and children making a giant mess at every given opportunity, forcing your older Sims to be driven by their insatiable compulsion to mop things, this mod will lessen the autonomy on the interaction for Sims with most traits. For a handful of selected traits, the autonomy for mess making is completely removed.

Traits disqualified from autonomous mess making (with Reasons):

Angelic Toddler (too nice)
Charmer Toddler (too nice)
Neat (goes without saying)
Good (also too nice)
Squeamish (because ew)
Perfectionist (messiness does not jive with perfection)
Proper (these Sims would find such a thing uncouth)
Lazy (2 lazy 2 do mess)
Speed Cleaner Reward Trait (see above entry for Neat)
Responsible Life Skill (obvious)
Good Manners Life Skill (also obvious)
Stoic Trait (Kuttoe) (too silly for them)
Calm Trait (Kuttoe) (they just don't have the gusto to be messy)
Dislikes Mischief (not very into misbehavior)
Dislikes Painting (why would you play with paint if you hate it?)
Kids with High Confidence or Self Esteem (well adjusted and not driven to misbehave)
Fairy Children/Toddlers (because in my view they would care about their environment too much to mess it up)

In addition to the blacklisted traits, the autonomy for other Sims has been lessened in a few different ways:

Cooldown extended so that Sims who are allowed to do it can only do it about once per day at most
Sims will only make messes if their mood is Bored, Playful, Angry, or Fine
Shouldn't make messes outside if it's snowing
Fun advertisement lowered so the interaction is less desirable in general unless the Sim has very low fun

Requirements:

Game Version At or Above 126.58

Requires the Parenthood game pack because otherwise you don't need this anyway.

Less "Make a Mess"