diff --git a/tools/chafa/chafa.c b/tools/chafa/chafa.c
index 45d0dec9..a557e855 100644
--- a/tools/chafa/chafa.c
+++ b/tools/chafa/chafa.c
@@ -448,23 +448,19 @@ print_summary (void)
 
     "\nSize and layout:\n"
 
-    "  -C, --center=BOOL  Center images horizontally in the view [on, off]. Defaults\n"
-    "                     to off.\n"
+    "  -C, --center=BOOL  Center images horizontally in view [on, off]. Default off.\n"
     "      --clear        Clear screen before processing each file.\n"
-    "      --fit-width    Fit images to the view's width, potentially exceeding its\n"
-    "                     height.\n"
+    "      --fit-width    Fit images to view's width, possibly exceeding its height.\n"
     "      --font-ratio=W/H  Target font's width/height ratio. Can be specified as\n"
     "                     a real number or a fraction. Defaults to 1/2.\n"
     "      --margin-bottom=NUM  When terminal size is detected, reserve at least NUM\n"
     "                     rows at the bottom as a safety margin. Can be used to\n"
     "                     prevent images from scrolling out. Defaults to 1.\n"
     "      --margin-right=NUM  When terminal size is detected, reserve at least NUM\n"
-    "                     columns on the right-hand side as a safety margin. Defaults\n"
-    "                     to 0.\n"
-    "      --scale=NUM    Scale image, respecting terminal's maximum dimensions. 1.0\n"
-    "                     approximates original pixel dimensions. Specify \"max\" to\n"
-    "                     use all available space. Defaults to 1.0 for pixel graphics\n"
-    "                     and 4.0 for symbols.\n"
+    "                     columns safety margin on right-hand side. Defaults to 0.\n"
+    "      --scale=NUM    Scale image, respecting view's dimensions. 1.0 approximates\n"
+    "                     image's pixel dimensions. Specify \"max\" to fit view.\n"
+    "                     Defaults to 1.0 for pixel graphics and 4.0 for symbols.\n"
     "  -s, --size=WxH     Set maximum image dimensions in columns and rows. By\n"
     "                     default this will be equal to the view size.\n"
     "      --stretch      Stretch image to fit output dimensions; ignore aspect.\n"
@@ -478,13 +474,12 @@ print_summary (void)
 
     "      --animate=BOOL  Whether to allow animation [on, off]. Defaults to on.\n"
     "                     When off, will show a still frame from each animation.\n"
-    "  -d, --duration=SECONDS  The time to show each file. If showing a single file,\n"
+    "  -d, --duration=SECONDS  How long to show each file. If showing a single file,\n"
     "                     defaults to zero for a still image and infinite for an\n"
     "                     animation. For multiple files, defaults to zero. Animations\n"
     "                     will always be played through at least once.\n"
-    "      --speed=SPEED  Set the speed animations will play at. This can be\n"
-    "                     either a unitless multiplier, or a real number followed\n"
-    "                     by \"fps\" to apply a specific framerate.\n"
+    "      --speed=SPEED  Animation speed. Either a unitless multiplier, or a real\n"
+    "                     number followed by \"fps\" to apply a specific framerate.\n"
     "      --watch        Watch a single input file, redisplaying it whenever its\n"
     "                     contents change. Will run until manually interrupted\n"
     "                     or, if --duration is set, until it expires.\n"
@@ -505,12 +500,10 @@ print_summary (void)
     "      --dither-intensity=NUM  Multiplier for dither intensity [0.0 - inf].\n"
     "                     Defaults to 1.0.\n"
     "      --fg=COLOR     Foreground color of display (color name or hex).\n"
-    "      --invert       Invert video. For display with bright backgrounds in\n"
-    "                     color modes 2 and none. Swaps --fg and --bg.\n"
+    "      --invert       Swaps --fg and --bg. Useful with light terminal background.\n"
     "  -p, --preprocess=BOOL  Image preprocessing [on, off]. Defaults to on with 16\n"
     "                     colors or lower, off otherwise.\n"
-    "  -t, --threshold=NUM  Threshold above which full transparency will be used\n"
-    "                     [0.0 - 1.0].\n"
+    "  -t, --threshold=NUM  Lower threshold for full transparency [0.0 - 1.0].\n"
 
     "\nResource allocation:\n"