diff --git a/project/Core/Src/mqtt_application.c b/project/Core/Src/mqtt_application.c
index 6692046..4ecaea8 100644
--- a/project/Core/Src/mqtt_application.c
+++ b/project/Core/Src/mqtt_application.c
@@ -61,7 +61,7 @@ static const char* TAG = "MQTT";
 /**
  * @brief callback function for publishing data
  *
- * @param[in] arg
+ * @param[in] arg       User supplied argument to connection callback
  * @param[in] result    Whether the publish was successful or not
  */
 static void mqtt_pub_request_cb(void* arg, err_t result) {
@@ -73,7 +73,7 @@ static void mqtt_pub_request_cb(void* arg, err_t result) {
  * Publishes the names of all the .bmp and .gif files on the topic getImageList
  *
  * @param[in] client    Pointer to the MQTT client
- * @param[in] arg
+ * @param[in] arg       Additional argument to pass to the callback function
  */
 static void publish_data(mqtt_client_t* client, void* arg) {
     char pub_payload[200] = {0};
@@ -101,7 +101,7 @@ static void publish_data(mqtt_client_t* client, void* arg) {
  * @brief Handles incoming publish
  * Callback function for when data was published to a subscribed topic
  *
- * @param[in] arg
+ * @param[in] arg       User supplied argument to connection callback
  * @param[in] topic     The topic on which an incoming publish was received
  * @param[in] tot_len   Length of the incoming data
  */
@@ -132,7 +132,7 @@ static void mqtt_incoming_publish_cb(void* arg, const char* topic, uint32_t tot_
  * @brief Handles incoming publish data
  * Handles the received data from a publish to a subscribed topic
  *
- * @param[in] arg
+ * @param[in] arg       User supplied argument to connection callback
  * @param[in] data      The incoming data
  * @param[in] len       Length of the data
  * @param[in] flags     Whether this is the last fragment of the incoming data
@@ -190,8 +190,8 @@ static void mqtt_incoming_data_cb(void* arg, const uint8_t* data, uint16_t len,
 /**
  * @brief Callback function for outgoing subscribe request
  *
- * @param[in] arg
- * @param[in] result
+ * @param[in] arg       User supplied argument to connection callback
+ * @param[in] result    Result code for the subscribe request
  */
 static void mqtt_sub_request_cb(void* arg, err_t result) {
     LOG_DEBUG(TAG, "Subscribe result: %d", result);
@@ -203,7 +203,7 @@ static void mqtt_sub_request_cb(void* arg, err_t result) {
  * subscribes to the input topics and calls the publish_data function.
  *
  * @param[in] client    Pointer to the MQTT client
- * @param[in] arg
+ * @param[in] arg       User supplied argument to connection callback
  * @param[in] status    Connect result code or disconnection notification
  */
 static void mqtt_connection_cb(mqtt_client_t* client, void* arg, mqtt_connection_status_t status) {