diff --git a/include/psa/crypto.h b/include/psa/crypto.h
index c45fccd4b..8e20013a2 100755
--- a/include/psa/crypto.h
+++ b/include/psa/crypto.h
@@ -1073,7 +1073,24 @@ psa_status_t psa_cipher_abort(psa_cipher_operation_t *operation);
  * @{
  */
 
-// This macro calculates the encryption output size according to given algorithm
+
+/** AEAD Encrypted data size
+ *
+ * This macro calculates the encrypted data size according to given algorithm
+ * and plaintext_length.
+ *
+ *
+ * \param alg                 The AEAD algorithm to compute
+ *                            (\c PSA_ALG_XXX value such that
+ *                            #PSA_ALG_IS_AEAD(alg) is true).
+ * \param plaintext_length    Size of \p plaintext in bytes.
+ *
+ * \return If the algorithm is PSA_ALG_GCM the encrypted data size is 
+ *         plaintext_length plus 16-bytes for tag.
+ *         If the algorithm is PSA_ALG_CCM the encrypted data size is 
+ *         plaintext_length plus 16-bytes for tag.
+ *         Otherwise return zero.
+ */
 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(alg, plaintext_length)     \
     ((alg) == PSA_ALG_GCM ? (plaintext_length) + 16 :           \
      (alg) == PSA_ALG_CCM ? (plaintext_length) + 16 :           \
@@ -1132,7 +1149,23 @@ psa_status_t psa_aead_encrypt( psa_key_slot_t key,
                                size_t ciphertext_size,
                                size_t *ciphertext_length );
 
-// This macro calculates the decryption output size according to given algorithm
+/** AEAD Decrypted data size
+ *
+ * This macro calculates the decrypted data size according to given algorithm
+ * and ciphertext_length.
+ *
+ *
+ * \param alg                 The AEAD algorithm to compute
+ *                            (\c PSA_ALG_XXX value such that
+ *                            #PSA_ALG_IS_AEAD(alg) is true).
+ * \param ciphertext_length    Size of \p ciphertext in bytes.
+ *
+ * \return If the algorithm is PSA_ALG_GCM the decrypted data size is 
+ *         ciphertext_length minus 16-bytes for tag.
+ *         If the algorithm is PSA_ALG_CCM the decrypted data size is 
+ *         ciphertext_length minus 16-bytes for tag.
+ *         Otherwise return zero.
+ */
 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(alg, ciphertext_length)     \
     ((alg) == PSA_ALG_GCM ? (ciphertext_length) - 16 :           \
      (alg) == PSA_ALG_CCM ? (ciphertext_length) - 16 :           \