update

Author: LadyBluenotes

src/routes/reference/store-utilities/modify-mutable.mdx

@@ -38,16 +38,15 @@ Mutable store to modify.
 
 - **Type:** `(state: T) => T`
 
-Modifier applied to the mutable store.
+Modifier applied to the mutable store. For direct mutation-style modifiers, the return value is ignored.
 
 ## Return value
 
 - **Type:** `void`
 
 ## Behavior
 
-- `modifyMutable` runs inside a [`batch`](/reference/reactive-utilities/batch).
-- Dependent computations update after the modifier completes.
+- `modifyMutable` runs inside a [`batch`](/reference/reactive-utilities/batch), so multiple changes notify dependents after the modifier completes, and the modifier receives the unwrapped underlying state object instead of the proxy.
 - The modifier can be a function returned by helpers such as [`reconcile`](/reference/store-utilities/reconcile) or [`produce`](/reference/store-utilities/produce).
 
 ## Examples