diff --git a/include/openthread/instance.h b/include/openthread/instance.h
index e2cc51602..234ee3428 100644
--- a/include/openthread/instance.h
+++ b/include/openthread/instance.h
@@ -52,7 +52,7 @@ extern "C" {
  *
  * @note This number versions both OpenThread platform and user APIs.
  */
-#define OPENTHREAD_API_VERSION (476)
+#define OPENTHREAD_API_VERSION (477)
 
 /**
  * @addtogroup api-instance
diff --git a/include/openthread/platform/radio.h b/include/openthread/platform/radio.h
index 8f7f38f9a..7cef06b9d 100644
--- a/include/openthread/platform/radio.h
+++ b/include/openthread/platform/radio.h
@@ -865,6 +865,17 @@ otError otPlatRadioReceive(otInstance *aInstance, uint8_t aChannel);
 /**
  * Schedule a radio reception window at a specific time and duration.
  *
+ * After a radio reception is successfully scheduled for a future time and duration, a subsequent call to this
+ * function MUST be handled as follows:
+ *
+ * - If the start time of the previously scheduled reception window has not yet been reached, the new call to
+ *   `otPlatRadioReceiveAt()` MUST cancel the previous schedule, effectively replacing it.
+ *
+ * - If the start of the previous window has already passed, the previous receive schedule is already being executed
+ *   by the radio and MUST NOT be replaced or impacted. The new call to `otPlatRadioReceiveAt()` would then schedule
+ *   a new future receive window. In particular, if the new `otPlatRadioReceiveAt()` call occurs after the start
+ *   but while still within the previous reception window, the ongoing reception window MUST NOT be impacted.
+ *
  * @param[in]  aChannel   The radio channel on which to receive.
  * @param[in]  aStart     The receive window start time relative to the local
  *                        radio clock, see `otPlatRadioGetNow`. The radio
@@ -879,7 +890,7 @@ otError otPlatRadioReceive(otInstance *aInstance, uint8_t aChannel);
  *                        reception has either succeeded or failed.
  *
  * @retval OT_ERROR_NONE    Successfully scheduled receive window.
- * @retval OT_ERROR_FAILED  The receive window could not be scheduled.
+ * @retval OT_ERROR_FAILED  The receive window could not be scheduled. For example, if @p aStart is in the past.
  */
 otError otPlatRadioReceiveAt(otInstance *aInstance, uint8_t aChannel, uint32_t aStart, uint32_t aDuration);