diff --git a/output/output_analog.c b/output/output_analog.c
index 4a6585bf..b9c3c7c2 100644
--- a/output/output_analog.c
+++ b/output/output_analog.c
@@ -216,7 +216,7 @@ static int event(struct output *o, int event_type, char **data_out,
 
 struct output_format output_analog = {
 	"analog",
-	"Analog data",
+	"Analog data (takes argument, default 10)",
 	DF_ANALOG,
 	init,
 	data,
diff --git a/output/output_text.c b/output/output_text.c
index cc3cb4e1..3c3fbb50 100644
--- a/output/output_text.c
+++ b/output/output_text.c
@@ -306,7 +306,7 @@ static int data_hex(struct output *o, char *data_in, uint64_t length_in,
 
 struct output_format output_text_bits = {
 	"bits",
-	"Text (bits)",
+	"Bits (takes argument, default 64)",
 	DF_LOGIC,
 	init_bits,
 	data_bits,
@@ -315,7 +315,7 @@ struct output_format output_text_bits = {
 
 struct output_format output_text_hex = {
 	"hex",
-	"Text (hexadecimal)",
+	"Hexadecimal (takes argument, default 256)",
 	DF_LOGIC,
 	init_hex,
 	data_hex,