diff --git a/twitter.api.php b/twitter.api.php
index dd3c9bc..8a0d4db 100644
--- a/twitter.api.php
+++ b/twitter.api.php
@@ -28,11 +28,72 @@ function hook_twitter_accounts($account) {}
 function hook_twitter_status_save($status) {}
 
 /**
- * Notifies of a saved twitter account.
+ * Notify of a saved twitter account.
+ *
+ * This hook is invoked by twitter_account_save() whenever a new Twitter
+ * account is added or an existing one updated (on new statuses being imported
+ * or import settings being changed).
  *
  * @param array $values
- *   Merged Drupal and Twitter account values.
+ *   An associative array containing, for new accounts or for accounts being
+ *   updated when new statuses are imported:
+ *   - screen_name: (string) Twitter "handle", e.g. 'juampytest'.
+ *   - name: (string) display name, e.g. 'Juampy Test Account'.
+ *   - location: (string) location, if any.
+ *   - description: (string) description, if any.
+ *   - followers_count: (int) the number of followers.
+ *   - friends_count: (int) the number of accounts given account is following.
+ *   - statuses_count: (int) the number of statuses.
+ *   - favourites_count: (int) the number of favorited statuses (note British
+ *     spelling here).
+ *   - url: (string) URL, if any.
+ *   - protected: (int 0|1) whether the account is protected.
+ *   - profile_image_url: (string) profile image URL; may point to one of
+ *     default images.
+ *   - profile_background_color: (string) hex color code, e.g. 'BEDEAD'.
+ *   - profile_text_color: (string) hex color code, e.g. 'BEDEAD'.
+ *   - profile_link_color: (string) hex color code, e.g. 'BEDEAD'.
+ *   - profile_sidebar_fill_color: (string) hex color code, e.g. 'BEDEAD'.
+ *   - profile_sidebar_border_color: (string) hex color code, e.g. 'BEDEAD'.
+ *   - profile_background_image_url: (string) profile background image URL; may
+ *     point to one of default backgrounds.
+ *   - profile_background_tile: (int 0|1) whether the background image is
+ *     tiled. How exactly does this setting work?
+ *   - verified: (int 0|1) whether the account is verified.
+ *   - created_at: (string) the time account was created, e.g.
+ *     'Thu Oct 13 10:21:00 +0000 2011'.
+ *   - created_time: (int) UNIX timestamp of account creation time, e.g.
+ *     1318501260.
+ *   - utc_offset: (int) timezone offset in seconds, e.g. 7200.
+ *   - twitter_uid: (int) Twitter user ID of the account, e.g. 390017783.
+ *   In addition to that, $values for authenticated accounts contains also:
+ *   - oauth_token: (string) OAuth token.
+ *   - oauth_token_secret: (string) OAuth secret.
+ *   For new accounts being added, $values contains also:
+ *   - uid: (string) user ID of the user adding the account, e.g. '1'. NOTE:
+ *     this is not necessarily connected to the account being saved and may
+ *     well be administrator's user ID. The presence of this key, however, lets
+ *     you tell apart new accounts from accounts being updated.
+ *   For accounts whose import settings are being updated on
+ *   admin/config/services/twitter page, $values contains ONLY the following
+ *   keys:
+ *   - screen_name: (string) Twitter "handle", e.g. 'juampytest'.
+ *   - import: (int 0|1) whether statuses of this account are being imported.
+ *   - mention: (int 0|1) (only for authenticated accounts) whether mentions of
+ *     this account are being imported.
+ *   - twitter_uid: (string) Twitter user ID of the account, e.g. '390017783'.
+ *   Note that pressing 'Save changes' button saves all accounts on the page,
+ *   regardless of whether the settings have been changed or not.
+ *
+ * @ingroup hooks
  *
  * @see twitter_account_save()
  */
-function hook_twitter_account_save($values) {}
+function hook_twitter_account_save($values) {
+  if (isset($values['uid'])) {
+    watchdog('twitter', 'A new Twitter account %handle has been added.', array('%handle' => $values['screen_name']));
+  }
+  else {
+    watchdog('twitter', 'Twitter account %handle has been updated.', array('%handle' => $values['screen_name']));
+  }
+}