diff --git a/crates/assistant2/src/tool_use.rs b/crates/assistant2/src/tool_use.rs
index d13c711d85adb3540d044f0ea5a41cc2053be7f5..cec6623aea68907fbf4db5fe9faedf5dad4783fb 100644
--- a/crates/assistant2/src/tool_use.rs
+++ b/crates/assistant2/src/tool_use.rs
@@ -209,7 +209,7 @@ impl ToolUseState {
         if let Some(tool) = self.tools.tool(tool_name, cx) {
             tool.ui_text(input).into()
         } else {
-            "Unknown tool".into()
+            format!("Unknown tool {tool_name:?}").into()
         }
     }