diff --git a/java_tools/tune-tools/src/main/java/com/rusefi/tools/tune/TuneCanTool.java b/java_tools/tune-tools/src/main/java/com/rusefi/tools/tune/TuneCanTool.java
index 81af202718..fc6cedd21d 100644
--- a/java_tools/tune-tools/src/main/java/com/rusefi/tools/tune/TuneCanTool.java
+++ b/java_tools/tune-tools/src/main/java/com/rusefi/tools/tune/TuneCanTool.java
@@ -29,6 +29,12 @@ import static com.rusefi.ConfigFieldImpl.unquote;
 import static com.rusefi.config.Field.niceToString;
 import static com.rusefi.tools.tune.WriteSimulatorConfiguration.INI_FILE_FOR_SIMULATOR;
 
+/**
+ * this command line utility compares two TS calibration files and produces .md files with C++ source code of the difference between those two files.
+ *
+ * Base 'default settings' file is msq generated by WriteSimulatorConfiguration.java with .xml extension but a real .msq could probably be used instead.
+ * Second calibration file which contains desired base calibrations is a native TS calibration file.
+ */
 public class TuneCanTool {
     private static final Logging log = getLogging(TuneCanTool.class);