diff --git a/autocomplete/fish_autocomplete b/autocomplete/fish_autocomplete
index b76e75f8..247c4c2f 100644
--- a/autocomplete/fish_autocomplete
+++ b/autocomplete/fish_autocomplete
@@ -81,7 +81,7 @@ complete -x -c lk -n '__fish_seen_subcommand_from agent a; and not __fish_seen_s
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from debugger dbg' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from debugger dbg; and not __fish_seen_subcommand_from start say chat-history transcript events status logs restart stop serve help h' -a 'start' -d 'Start the agent in the background and wait until it is ready'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l port -r -d 'Loopback port the session listens on (one session per port)'
-complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l idle-timeout -r -d 'Stop the session after this long without any command (0 to keep it running until `stop`)'
+complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l idle-timeout -r -d 'Stop the session after `DURATION` without any command, such as 30m, 2h, or 90s (0 keeps it running until stop)'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l json -s j -d 'Output as JSON'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start; and not __fish_seen_subcommand_from help h' -a 'help' -d 'Shows a list of commands or help for one command'
@@ -89,7 +89,7 @@ complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subco
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l port -r -d 'Loopback port the session listens on (one session per port)'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l json -s j -d 'Output as JSON'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l metrics -d 'Show latency metrics: time to first token per reply and how long each turn took'
-complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l timeout -r -d 'Give up waiting for the agent\'s reply after this long'
+complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l timeout -r -d 'Give up waiting for the agent\'s reply after `DURATION`, such as 2m or 90s'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l logs -d 'Interleave agent log lines emitted during the turn'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say; and not __fish_seen_subcommand_from help h' -a 'help' -d 'Shows a list of commands or help for one command'
@@ -284,7 +284,7 @@ complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subco
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and not __fish_seen_subcommand_from start say chat-history transcript events status logs restart stop serve help h' -a 'start' -d 'Start the agent in the background and wait until it is ready'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l port -r -d 'Loopback port the session listens on (one session per port)'
-complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l idle-timeout -r -d 'Stop the session after this long without any command (0 to keep it running until `stop`)'
+complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l idle-timeout -r -d 'Stop the session after `DURATION` without any command, such as 30m, 2h, or 90s (0 keeps it running until stop)'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l json -s j -d 'Output as JSON'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from start; and not __fish_seen_subcommand_from help h' -a 'help' -d 'Shows a list of commands or help for one command'
@@ -292,7 +292,7 @@ complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subco
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l port -r -d 'Loopback port the session listens on (one session per port)'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l json -s j -d 'Output as JSON'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l metrics -d 'Show latency metrics: time to first token per reply and how long each turn took'
-complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l timeout -r -d 'Give up waiting for the agent\'s reply after this long'
+complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l timeout -r -d 'Give up waiting for the agent\'s reply after `DURATION`, such as 2m or 90s'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l logs -d 'Interleave agent log lines emitted during the turn'
 complete -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say' -f -l help -s h -d 'show help'
 complete -x -c lk -n '__fish_seen_subcommand_from agent a; and __fish_seen_subcommand_from daemon dbg; and __fish_seen_subcommand_from say; and not __fish_seen_subcommand_from help h' -a 'help' -d 'Shows a list of commands or help for one command'
diff --git a/cmd/lk/debugger.go b/cmd/lk/debugger.go
index 04cbb4f1..61e3cb91 100644
--- a/cmd/lk/debugger.go
+++ b/cmd/lk/debugger.go
@@ -68,7 +68,7 @@ var sessionPortFlag = &cli.IntFlag{
 var sessionIdleFlag = &cli.DurationFlag{
 	Name:  "idle-timeout",
 	Value: defaultIdleTimeout,
-	Usage: "Stop the session after this long without any command (0 to keep it running until `stop`)",
+	Usage: "Stop the session after `DURATION` without any command, such as 30m, 2h, or 90s (0 keeps it running until stop)",
 }
 
 var sessionMetricsFlag = &cli.BoolFlag{
@@ -182,7 +182,7 @@ be piped on stdin:
 				&cli.DurationFlag{
 					Name:  "timeout",
 					Value: defaultSayTimeout,
-					Usage: "Give up waiting for the agent's reply after this long",
+					Usage: "Give up waiting for the agent's reply after `DURATION`, such as 2m or 90s",
 				},
 				&cli.BoolFlag{
 					Name:  "logs",