Render tool output as terminal text

src/agent.rs

@@ -1472,7 +1472,7 @@ fn split_tool_results(result: &str) -> Vec<String> {
 }
 
 pub(crate) fn bounded_tool_text(text: &str, limit: usize) -> String {
-    let mut output = text.replace('\n', " ");
+    let mut output = text.to_owned();
     if output.chars().count() > limit {
         output = output
             .chars()
@@ -1489,7 +1489,12 @@ pub(crate) fn tool_parameters(call: &ToolCall) -> String {
         .find_map(|name| string(call, name).map(|value| (name, value)))
         .map_or_else(
             || bounded_tool_text(&Value::Object(call.arguments.clone()).to_string(), 240),
-            |(name, value)| format!("{name}: {}", bounded_tool_text(value, 240)),
+            |(name, value)| {
+                format!(
+                    "{name}: {}",
+                    bounded_tool_text(&value.replace('\n', " "), 240)
+                )
+            },
         )
 }
 
@@ -1947,6 +1952,15 @@ mod tests {
         assert!(!SHELL_ENV_ALLOWLIST.contains(&"SSH_AUTH_SOCK"));
     }
 
+    #[test]
+    fn tool_output_keeps_terminal_lines_but_parameter_summaries_do_not() {
+        assert_eq!(bounded_tool_text("one\ntwo", 20), "one\ntwo");
+        assert_eq!(
+            tool_parameters(&call("bash", [("command", "one\ntwo")])),
+            "command: one two"
+        );
+    }
+
     #[test]
     fn denial_and_stop_cancel_commands_awaiting_approval() {
         let directory = std::env::temp_dir().join(format!(

src/app/view/chat.rs

@@ -141,6 +141,11 @@ impl App {
                                     })
                                     .padding(0)
                                     .size(14)
+                                    .font(if message.tool {
+                                        iced::Font::MONOSPACE
+                                    } else {
+                                        iced::Font::DEFAULT
+                                    })
                                     .style(selectable_text_style),
                             );
                         } else {
@@ -503,7 +508,7 @@ fn tool_cards(cards: Vec<crate::agent::ToolCard>) -> Element<'static, Message> {
         .spacing(5);
         if let Some(result) = card.result {
             let bounded = crate::agent::bounded_tool_text(&result, 1_200);
-            content = content.push(text(bounded).size(12));
+            content = content.push(text(bounded).font(iced::Font::MONOSPACE).size(12));
         }
         rows = rows.push(container(content).padding(10).width(Length::Fill));
     }