diff --git a/include/psa/crypto_builtin.h b/include/psa/crypto_builtin.h
index 7b66172..b3bc140 100644
--- a/include/psa/crypto_builtin.h
+++ b/include/psa/crypto_builtin.h
@@ -1,6 +1,15 @@
 /*
- *  Context structure declaration of the software-based drivers called
- *  through the PSA Crypto driver dispatch layer.
+ *  Context structure declaration of the Mbed TLS software-based PSA drivers
+ *  called through the PSA Crypto driver dispatch layer.
+ *
+ * \note This file may not be included directly. Applications must
+ * include psa/crypto.h.
+ *
+ * \note This header and its content is not part of the Mbed TLS API and
+ * applications must not depend on it. Its main purpose is to define the
+ * multi-part state objects of the Mbed TLS software-based PSA drivers. The
+ * definition of these objects are then used by crypto_struct.h to define the
+ * implementation-defined types of PSA multi-part state objects.
  */
 /*
  *  Copyright The Mbed TLS Contributors