Add some method descriptions from neer's "Common Variables and Functions"

code/__DEFINES/misc.dm

@@ -185,10 +185,15 @@ GLOBAL_LIST_EMPTY(bloody_footprints_cache)
 //subtypesof(), typesof() without the parent path
 #define subtypesof(typepath) ( typesof(typepath) - typepath )
 
-//Gets the turf this atom inhabits
+/// Get the turf that `A` resides in, regardless of any containers.
+///
+/// Use in favor of `A.loc` or `src.loc` so that things work correctly when
+/// stored inside an inventory, locker, or other container.
 #define get_turf(A) (get_step(A, 0))
 
-//Same as above except gets the area instead
+/// Get the ultimate area of `A`, similarly to [get_turf].
+///
+/// Use instead of `A.loc.loc`.
 #define get_area(A) (isarea(A) ? A : get_step(A, 0)?.loc)
 
 //Ghost orbit types:

code/__HELPERS/_lists.dm

@@ -229,7 +229,7 @@
 
 	return null
 
-//Pick a random element from the list and remove it from the list.
+/// Pick a random element from the list and remove it from the list.
 /proc/pick_n_take(list/L)
 	RETURN_TYPE(L[_].type)
 	if(L.len)

code/__HELPERS/mobs.dm

@@ -250,7 +250,10 @@ GLOBAL_LIST_EMPTY(species_list)
 	return ..()
 
 
-///Timed action involving one mob user. Target is optional.
+/// Timed action involving one mob user. Target is optional.
+///
+/// Checks that `user` does not move, change hands, get stunned, etc. for the
+/// given `delay`. Returns `TRUE` on success or `FALSE` on failure.
 /proc/do_after(mob/user, delay, atom/target, timed_action_flags = NONE, progress = TRUE, datum/callback/extra_checks)
 	if(!user)
 		return FALSE

code/game/objects/items.dm

@@ -454,6 +454,7 @@ GLOBAL_VAR_INIT(embedpocalypse, FALSE) // if true, all items will be able to emb
 /obj/item/proc/talk_into(mob/M, input, channel, spans, datum/language/language, list/message_mods)
 	return ITALICS | REDUCE_RANGE
 
+/// Called when a mob drops an item.
 /obj/item/proc/dropped(mob/user, silent = FALSE)
 	SHOULD_CALL_PARENT(TRUE)
 	for(var/X in actions)
@@ -478,8 +479,10 @@ GLOBAL_VAR_INIT(embedpocalypse, FALSE) // if true, all items will be able to emb
 	return
 
 /**
-  *called after an item is placed in an equipment slot
-
+  * Called after an item is placed in an equipment slot.
+  *
+  * Note that hands count as slots.
+  *
   * Arguments:
   * * user is mob that equipped it
   * * slot uses the slot_X defines found in setup.dm for items that can be placed in multiple slots