Improve documentation of psa_internal_allocate_key_slot
@@ -57,8 +57,11 @@ void psa_wipe_all_key_slots( void );
/** Find a free key slot and mark it as in use.
*
- * \param[out] handle On success, a slot number that is not in use. This
- * value can be used as a handle to the slot.
+ * \param[out] handle On success, a slot number that can be used as a
+ * handle to the slot. The selected slot was not
+ * in use before. This function marks it as in use
+ * and otherwise leaves it in a freshly-initialized
+ * state.
* \param[out] p_slot On success, a pointer to the slot.
*
* \retval #PSA_SUCCESS
