diff --git a/apps/client/src/components/ui/agent-avatar-stack.test.tsx b/apps/client/src/components/ui/agent-avatar-stack.test.tsx
index 9a6460ab..39d446b1 100644
--- a/apps/client/src/components/ui/agent-avatar-stack.test.tsx
+++ b/apps/client/src/components/ui/agent-avatar-stack.test.tsx
@@ -43,6 +43,24 @@ describe("AgentAvatarStack", () => {
     expect(screen.getByText("Alice")).toBeDefined();
   });
 
+  it("showName=false: renders only the avatars, no inline name label", () => {
+    renderStack({
+      agent: { name: "Researcher", emoji: "🔬", avatarUrl: null },
+      launcher: { name: "Alice", avatarUrl: null },
+      aiChatId: "chat-1",
+      showName: false,
+    });
+
+    // The agent glyph is still rendered...
+    expect(screen.getByText("🔬")).toBeDefined();
+    // ...but neither the agent NOR the launcher inline name label is rendered
+    // (they live only in the hover tooltip, which is not mounted in the initial
+    // DOM) — guards against suppressing only the agent name and leaking the
+    // launcher name.
+    expect(screen.queryByText("Researcher")).toBeNull();
+    expect(screen.queryByText("Alice")).toBeNull();
+  });
+
   it("internal chat WITHOUT role: sparkles fallback + 'AI agent' + launcher", () => {
     const { container } = renderStack({
       agent: { name: "AI agent", avatarUrl: null },
diff --git a/apps/client/src/components/ui/agent-avatar-stack.tsx b/apps/client/src/components/ui/agent-avatar-stack.tsx
index 430c10c4..59ce252c 100644
--- a/apps/client/src/components/ui/agent-avatar-stack.tsx
+++ b/apps/client/src/components/ui/agent-avatar-stack.tsx
@@ -27,6 +27,9 @@ export interface LauncherInfo {
 const AGENT_COLOR = "violet";
 const GLYPH_SIZE = 38;
 const LAUNCHER_SIZE = 22;
+// How far the launcher avatar sticks out past the agent's bottom-right corner, so
+// the "human behind" reads as behind (lower z-index) yet stays clearly visible.
+const LAUNCHER_OVERHANG = 8;
 
 /**
  * The front avatar. Image-source priority (#300):
@@ -72,6 +75,9 @@ export interface AgentAvatarStackProps {
   // (e.g. the page-history row closes the history modal). Keeps this ui/ primitive
   // free of cross-feature coupling (inherited from the old AiAgentBadge, #143).
   onActivate?: () => void;
+  // Whether to render the inline name label next to the avatars (default true).
+  // Set false when the caller renders the name itself (e.g. the comment row).
+  showName?: boolean;
 }
 
 /**
@@ -87,6 +93,7 @@ export function AgentAvatarStack({
   launcher,
   aiChatId,
   onActivate,
+  showName = true,
 }: AgentAvatarStackProps) {
   const { t } = useTranslation();
   const setAiChatWindowOpen = useSetAtom(aiChatWindowOpenAtom);
@@ -117,13 +124,21 @@ export function AgentAvatarStack({
       })
     : t("AI agent {{name}}", { name: agent.name });
 
+  // The container is only enlarged when there is a launcher to overhang; with no
+  // human behind it stays tight at the agent glyph size.
+  const stackSize = launcher ? GLYPH_SIZE + LAUNCHER_OVERHANG : GLYPH_SIZE;
+
   const stack = (
     <Box
       pos="relative"
       style={{
-        width: GLYPH_SIZE,
-        height: GLYPH_SIZE,
+        width: stackSize,
+        height: stackSize,
         flexShrink: 0,
+        // Center the (in-flow) agent glyph vertically so it lines up with its
+        // name label; the absolutely-positioned launcher is unaffected by flex.
+        display: "flex",
+        alignItems: "center",
         cursor: clickable ? "pointer" : undefined,
       }}
       {...(clickable
@@ -150,7 +165,16 @@ export function AgentAvatarStack({
           />
         </Box>
       )}
-      <Box pos="relative" style={{ zIndex: 1 }}>
+      {/* Pin the agent glyph to the top-left at its own size; the launcher then
+          overhangs it by LAUNCHER_OVERHANG at the bottom-right and stays visible. */}
+      <Box
+        style={{
+          position: "relative",
+          zIndex: 1,
+          width: GLYPH_SIZE,
+          height: GLYPH_SIZE,
+        }}
+      >
         <AgentGlyph agent={agent} />
       </Box>
     </Box>
@@ -161,21 +185,23 @@ export function AgentAvatarStack({
       <Tooltip label={tooltip} withArrow>
         {stack}
       </Tooltip>
-      <Group gap={4} wrap="nowrap" style={{ minWidth: 0 }}>
-        <Text size="xs" fw={600} lineClamp={1} lh={1.2}>
-          {agent.name}
-        </Text>
-        {launcher && (
-          <>
-            <Text size="xs" c="dimmed" fw={400} aria-hidden>
-              ·
-            </Text>
-            <Text size="xs" c="dimmed" fw={400} lineClamp={1} lh={1.2}>
-              {launcher.name}
-            </Text>
-          </>
-        )}
-      </Group>
+      {showName && (
+        <Group gap={4} wrap="nowrap" style={{ minWidth: 0 }}>
+          <Text size="xs" fw={600} lineClamp={1} lh={1.2}>
+            {agent.name}
+          </Text>
+          {launcher && (
+            <>
+              <Text size="xs" c="dimmed" fw={400} aria-hidden>
+                ·
+              </Text>
+              <Text size="xs" c="dimmed" fw={400} lineClamp={1} lh={1.2}>
+                {launcher.name}
+              </Text>
+            </>
+          )}
+        </Group>
+      )}
     </Group>
   );
 }
diff --git a/apps/client/src/features/comment/components/comment-list-item.test.tsx b/apps/client/src/features/comment/components/comment-list-item.test.tsx
index d1034e4a..1826e4ae 100644
--- a/apps/client/src/features/comment/components/comment-list-item.test.tsx
+++ b/apps/client/src/features/comment/components/comment-list-item.test.tsx
@@ -41,19 +41,39 @@ function renderItem(comment: IComment) {
 }
 
 describe("CommentListItem — agent avatar stack", () => {
-  it('renders the agent avatar stack when createdSource === "agent"', () => {
-    // External-MCP shape: agent is the account itself, no launcher behind.
+  it('flips the hierarchy for an agent comment: agent primary, launcher shown once', () => {
+    // Internal-chat shape with DISTINCT names so absence-of-duplication is
+    // assertable: creator is the human "Alice", the acting agent is "Researcher".
     renderItem(
       baseComment({
+        creator: { id: "user-1", name: "Alice", avatarUrl: null } as any,
+        createdSource: "agent",
+        aiChatId: "chat-1",
+        agent: { name: "Researcher", emoji: "🔬", avatarUrl: null },
+        launcher: { name: "Alice", avatarUrl: null },
+      }),
+    );
+    // The AGENT is the primary label (the flipped hierarchy).
+    expect(screen.getByText("Researcher")).toBeDefined();
+    // The human launcher name shows exactly once — it is no longer duplicated as
+    // a separate creator name (that duplication is the bug this fixes).
+    expect(screen.getAllByText("Alice").length).toBe(1);
+  });
+
+  it('external MCP agent comment (no launcher): shows the agent name, no separator', () => {
+    // aiChatId null => external MCP: the agent IS the account, no human behind.
+    renderItem(
+      baseComment({
+        creator: { id: "bot-1", name: "MCP Bot", avatarUrl: null } as any,
         createdSource: "agent",
         aiChatId: null,
-        agent: { name: "Service Bot", avatarUrl: null },
+        agent: { name: "MCP Bot", avatarUrl: null },
         launcher: null,
       }),
     );
-    // The stack renders the agent name label (the creator name is also shown in
-    // the row header, so it appears more than once).
-    expect(screen.getAllByText("Service Bot").length).toBeGreaterThan(0);
+    expect(screen.getByText("MCP Bot")).toBeDefined();
+    // No launcher => no dimmed "·" separator in the header.
+    expect(screen.queryByText("·")).toBeNull();
   });
 
   it('does NOT render the stack for a normal user comment (createdSource "user")', () => {
diff --git a/apps/client/src/features/comment/components/comment-list-item.tsx b/apps/client/src/features/comment/components/comment-list-item.tsx
index 7167ebdb..072281bb 100644
--- a/apps/client/src/features/comment/components/comment-list-item.tsx
+++ b/apps/client/src/features/comment/components/comment-list-item.tsx
@@ -119,25 +119,44 @@ function CommentListItem({
   return (
     <Box ref={ref} pb={6}>
       <Group gap="xs">
-        <CustomAvatar
-          size="sm"
-          avatarUrl={comment.creator.avatarUrl}
-          name={comment.creator.name}
-        />
+        {comment.createdSource === "agent" && comment.agent ? (
+          <AgentAvatarStack
+            agent={comment.agent}
+            launcher={comment.launcher}
+            aiChatId={comment.aiChatId}
+            showName={false}
+          />
+        ) : (
+          <CustomAvatar
+            size="sm"
+            avatarUrl={comment.creator.avatarUrl}
+            name={comment.creator.name}
+          />
+        )}
 
         <div style={{ flex: 1 }}>
           <Group justify="space-between" wrap="nowrap">
             <Group gap={6} wrap="nowrap" style={{ minWidth: 0 }}>
-              <Text size="xs" fw={500} lineClamp={1} lh={1.2}>
-                {comment.creator.name}
-              </Text>
-
-              {comment.createdSource === "agent" && comment.agent && (
-                <AgentAvatarStack
-                  agent={comment.agent}
-                  launcher={comment.launcher}
-                  aiChatId={comment.aiChatId}
-                />
+              {comment.createdSource === "agent" && comment.agent ? (
+                <>
+                  <Text size="xs" fw={600} lineClamp={1} lh={1.2}>
+                    {comment.agent.name}
+                  </Text>
+                  {comment.launcher && (
+                    <>
+                      <Text size="xs" c="dimmed" fw={400} aria-hidden>
+                        ·
+                      </Text>
+                      <Text size="xs" c="dimmed" fw={400} lineClamp={1} lh={1.2}>
+                        {comment.launcher.name}
+                      </Text>
+                    </>
+                  )}
+                </>
+              ) : (
+                <Text size="xs" fw={500} lineClamp={1} lh={1.2}>
+                  {comment.creator.name}
+                </Text>
               )}
             </Group>