doc(wallet): Fixup docs for insert_tx

and add a disclaimer about safety for
`Wallet::tx_graph_mut`

crates/wallet/src/wallet/mod.rs

@@ -1215,9 +1215,11 @@ impl Wallet {
     /// which will be false if the same transaction already exists in the wallet's transaction
     /// graph. Any changes will be staged but not committed.
     ///
-    /// **WARNING**: manually inserting a transaction can influence the wallet's utxos and pending
-    /// balance if the tx is relevant to this wallet, but you won't know whether the resulting
-    /// txouts exist on chain until the tx is broadcast and the wallet synced via a chain source.
+    /// # Note
+    ///
+    /// By default the inserted `tx` won't be considered "canonical" because it's not known
+    /// whether the transaction exists in the best chain. To know whether it exists, the tx
+    /// must be broadcast to the network and the wallet synced via a chain source.
     pub fn insert_tx(&mut self, tx: Transaction) -> bool {
         let mut changeset = ChangeSet::default();
         changeset.append(self.indexed_graph.insert_tx(tx).into());
@@ -2432,6 +2434,11 @@ impl Wallet {
     }
 
     /// Get a mutable reference to the inner [`TxGraph`].
+    ///
+    /// **WARNING**: It's not recommended to make changes manually to the transaction
+    /// graph unless you know what you're doing, because it can cause the wallet to get
+    /// into a bad state. Changes to the inner [`TxGraph`] happen naturally as a result
+    /// of syncing with an external chain source and applying updates to the wallet.
     pub fn tx_graph_mut(&mut self) -> &mut TxGraph<ConfirmationTimeHeightAnchor> {
         self.indexed_graph.graph_mut()
     }