diff --git a/packages/ui/src/components/message-block.tsx b/packages/ui/src/components/message-block.tsx
index 1e476817..070b303c 100644
--- a/packages/ui/src/components/message-block.tsx
+++ b/packages/ui/src/components/message-block.tsx
@@ -434,7 +434,7 @@ function ToolCallItem(props: ToolCallItemProps) {
               <span class="tool-name">{toolName() || t("messageBlock.tool.unknown")}</span>
             </div>
 
-            <div class="flex items-center gap-2">
+            <div class="flex items-center gap-0">
               <Show when={taskSessionId()}>
                 <button
                   class="tool-call-header-button"
diff --git a/packages/ui/src/styles/messaging/tool-call.css b/packages/ui/src/styles/messaging/tool-call.css
index 8997f1e8..4c504b36 100644
--- a/packages/ui/src/styles/messaging/tool-call.css
+++ b/packages/ui/src/styles/messaging/tool-call.css
@@ -21,9 +21,9 @@
 
 .tool-call-header-button {
   background-color: transparent;
-  border: 1px solid var(--tool-call-border-color, var(--border-base));
   color: var(--text-secondary);
-  padding: 0.15rem 0.75rem;
+  border: 0;
+  padding: 0.1rem 0.35rem;
   border-radius: 0.375rem;
   font-size: 0.75rem;
   font-weight: var(--font-weight-semibold);
@@ -37,7 +37,6 @@
 
 .tool-call-header-button:hover:not(:disabled) {
   background-color: var(--surface-hover);
-  border-color: var(--accent-primary);
   color: var(--accent-primary);
 }