diff --git a/robosystems_client/models/sso_complete_request.py b/robosystems_client/models/sso_complete_request.py
index ea82740..7ed7114 100644
--- a/robosystems_client/models/sso_complete_request.py
+++ b/robosystems_client/models/sso_complete_request.py
@@ -18,7 +18,7 @@ class SSOCompleteRequest:
   Attributes:
       session_id (str): Temporary session ID from secure handoff
       browser_nonce (None | str | Unset): The nonce this browser minted when it started the bridge; its SHA-256 was
-          passed through the exchange as browser_nonce_hash.
+          passed through the exchange as browser_nonce_hash. Required to complete a handoff.
   """
 
   session_id: str
diff --git a/robosystems_client/models/sso_exchange_request.py b/robosystems_client/models/sso_exchange_request.py
index 0faef82..60c09e9 100644
--- a/robosystems_client/models/sso_exchange_request.py
+++ b/robosystems_client/models/sso_exchange_request.py
@@ -20,7 +20,8 @@ class SSOExchangeRequest:
       target_app (str): Target application identifier
       return_url (None | str | Unset): Optional return URL after authentication
       browser_nonce_hash (None | str | Unset): SHA-256 (hex) of a nonce the target app minted in the browser that is
-          signing in. Completion must present the nonce, so the handoff cannot be redeemed by any other browser.
+          signing in. Completion must present the nonce, so the handoff cannot be redeemed by any other browser; a session
+          exchanged without one cannot be completed.
   """
 
   token: str