diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 3e174f9c2e..4384a43102 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1191,6 +1191,9 @@ static psa_status_t psa_restrict_key_policy(
  * usage flags set in \p usage. If \p alg is nonzero, the key must allow
  * operations with this algorithm.
  *
+ *  In case of a persistent key, the function loads the description of the key
+ *  into a key slot if not already done.
+ *
  * On success, the access counter of the returned key slot is incremented by
  * one. It is the responsibility of the caller to call
  * psa_decrement_key_slot_access_count() when it does not access the key slot
diff --git a/library/psa_crypto_slot_management.h b/library/psa_crypto_slot_management.h
index d22e343bc0..8d3c3840a1 100644
--- a/library/psa_crypto_slot_management.h
+++ b/library/psa_crypto_slot_management.h
@@ -82,7 +82,8 @@ static inline int psa_key_id_is_volatile( psa_key_id_t key_id )
  *
  * \retval #PSA_SUCCESS
  *         The pointer to the key slot containing the description of the key
- *         identified by \p key was returned.
+ *         identified by \p key was returned. The key slot counter was
+ *         implemented.
  * \retval #PSA_ERROR_BAD_STATE
  *         The library has not been initialized.
  * \retval #PSA_ERROR_INVALID_HANDLE