diff --git a/README.md b/README.md
new file mode 100644
index 0000000..aa157ed
--- /dev/null
+++ b/README.md
@@ -0,0 +1,5 @@
+# installation
+
+```
+go install sneak.berlin/go/field@latest
+```
diff --git a/main.go b/main.go
index 68ddde3..e41459f 100644
--- a/main.go
+++ b/main.go
@@ -10,13 +10,13 @@ import (
 
 func main() {
 	if len(os.Args) < 2 {
-		fmt.Fprintf(os.Stderr, "usage: %s <field-number>", os.Args[0])
+		fmt.Fprintf(os.Stderr, "usage: %s <field-number>\n", os.Args[0])
 		os.Exit(1)
 	}
 
 	fieldNum, err := strconv.Atoi(os.Args[1])
 	if err != nil || fieldNum < 1 {
-		fmt.Fprintln(os.Stderr, "invalid field number:", os.Args[1])
+		fmt.Fprintln(os.Stderr, "error: invalid field number")
 		os.Exit(1)
 	}