diff --git a/ui/src/components/app-sidebar-agent-menu.ts b/ui/src/components/app-sidebar-agent-menu.ts
index ea58187e4e79..81263cd39cbf 100644
--- a/ui/src/components/app-sidebar-agent-menu.ts
+++ b/ui/src/components/app-sidebar-agent-menu.ts
@@ -135,9 +135,7 @@ function sidebarAgentMenuRows(params: {
       const agentId = normalizeAgentId(entry.id);
       return (
         agentId.toLowerCase().includes(query) ||
-        (params.identities.get(agentId)?.name?.trim() || normalizeAgentLabel(entry))
-          .toLowerCase()
-          .includes(query)
+        normalizeAgentLabel(entry, params.identities.get(agentId)).toLowerCase().includes(query)
       );
     });
     return { rows, showFilter: true };
@@ -164,7 +162,7 @@ function sidebarAgentMenuRows(params: {
 function renderAgentRow(agent: AgentMenuAgent, params: SidebarAgentMenuParams) {
   const agentId = normalizeAgentId(agent.id);
   const identity = params.identities.get(agentId) ?? null;
-  const label = identity?.name?.trim() || normalizeAgentLabel(agent);
+  const label = normalizeAgentLabel(agent, identity);
   const active = agentId === params.activeId;
   const unread = active ? 0 : params.agentUnreadCount(agentId);
   const approvals = params.agentApprovalCount(agentId);
diff --git a/ui/src/components/app-sidebar-render.ts b/ui/src/components/app-sidebar-render.ts
index 2ee931177593..affa9ad0fd55 100644
--- a/ui/src/components/app-sidebar-render.ts
+++ b/ui/src/components/app-sidebar-render.ts
@@ -82,8 +82,7 @@ export function renderAppSidebarBrand(host: AppSidebarRenderHost) {
     const agentId = normalizeAgentId(entry.id);
     return agentId !== cardAgentId && host.agentUnreadCount(agentId) > 0;
   });
-  const cardName =
-    cardIdentity?.name?.trim() || (cardAgent ? normalizeAgentLabel(cardAgent) : cardAgentId);
+  const cardName = cardAgent ? normalizeAgentLabel(cardAgent, cardIdentity) : cardAgentId;
   const approvalCount = host.sessionData.approvalBadgeSnapshot().agentCounts.get(cardAgentId) ?? 0;
   const gateway = host.sessionDataContext?.gateway;
   const avatarAuthToken = gateway
diff --git a/ui/src/components/sidebar-menus-render.ts b/ui/src/components/sidebar-menus-render.ts
index 45e29e83e677..82f618938d1f 100644
--- a/ui/src/components/sidebar-menus-render.ts
+++ b/ui/src/components/sidebar-menus-render.ts
@@ -84,7 +84,7 @@ export function renderSidebarAgentMenuForController(controller: SidebarMenusCont
     position,
     basePath: host.basePath,
     activeId,
-    activeName: identity?.name?.trim() || (agent ? normalizeAgentLabel(agent) : activeId),
+    activeName: agent ? normalizeAgentLabel(agent, identity) : activeId,
     agents,
     identities,
     filter: controller.agentMenuFilter,
diff --git a/ui/src/lib/agents/display.ts b/ui/src/lib/agents/display.ts
index d4658cc51b8e..2ba4e793cd4a 100644
--- a/ui/src/lib/agents/display.ts
+++ b/ui/src/lib/agents/display.ts
@@ -23,6 +23,8 @@ import { normalizeLowercaseStringOrEmpty, normalizeOptionalString } from "../str
 type AgentRosterEntry = {
   id: string;
   kind?: "agent" | "system";
+  name?: string;
+  identity?: { name?: string };
 };
 
 /** Ordinary agent targets; system rows remain available to diagnostic surfaces. */
@@ -319,13 +321,16 @@ type ConfigSnapshot = {
   };
 };
 
-export function normalizeAgentLabel(agent: {
-  id: string;
-  name?: string;
-  identity?: { name?: string };
-}) {
+export function normalizeAgentLabel(
+  agent: AgentRosterEntry,
+  hydratedIdentity?: { name?: string } | null,
+) {
+  // Roster labels own operator target identity; workspace identity only fills gaps.
   return (
-    normalizeOptionalString(agent.name) ?? normalizeOptionalString(agent.identity?.name) ?? agent.id
+    normalizeOptionalString(agent.name) ??
+    normalizeOptionalString(agent.identity?.name) ??
+    normalizeOptionalString(hydratedIdentity?.name) ??
+    agent.id
   );
 }
 
diff --git a/ui/src/test-helpers/app-sidebar-cases/agent-menu.ts b/ui/src/test-helpers/app-sidebar-cases/agent-menu.ts
index 317acdda20f9..db86b11d30e5 100644
--- a/ui/src/test-helpers/app-sidebar-cases/agent-menu.ts
+++ b/ui/src/test-helpers/app-sidebar-cases/agent-menu.ts
@@ -52,6 +52,52 @@ describe("AppSidebar agent chip", () => {
     expect(request).toHaveBeenCalledWith("agent.identity.get", { agentId: "main" });
   });
 
+  it("keeps the configured roster label when identity hydration returns a fallback", async () => {
+    const request = vi.fn(async (_method: string, params: { agentId: string }) =>
+      params.agentId === "main"
+        ? { agentId: "main", name: "Workspace Molty", avatar: "🦞" }
+        : { agentId: "rust-claw", name: "Assistant", avatar: "🦀" },
+    );
+    const gatewayHarness = createGatewayHarness({ request } as unknown as GatewayBrowserClient);
+    const agentIdentity = createAgentIdentityCapability(gatewayHarness.gateway);
+    const { sidebar } = await mountSidebar(
+      gatewayHarness.gateway,
+      createSessions("main", ["agent:main:main"]),
+      "panel",
+      {
+        defaultId: "main",
+        mainKey: "main",
+        scope: "per-sender",
+        agents: [{ id: "main" }, { id: "rust-claw", name: "rust-claw" }],
+      },
+      [],
+      agentIdentity,
+    );
+
+    sidebar.connected = true;
+    await vi.waitFor(() => {
+      expect(sidebar.querySelector(".sidebar-agent-card__name")?.textContent?.trim()).toBe(
+        "Workspace Molty",
+      );
+    });
+    sidebar.querySelector<HTMLButtonElement>(".sidebar-agent-card__main")?.click();
+    await vi.waitFor(() => {
+      expect(request).toHaveBeenCalledWith("agent.identity.get", { agentId: "rust-claw" });
+      const labels = [
+        ...sidebar.querySelectorAll(".sidebar-agent-menu .agent-select__option-label"),
+      ].map((element) => element.textContent?.trim());
+      expect(labels).toEqual(["Workspace Molty", "rust-claw"]);
+    });
+    await vi.waitFor(() => {
+      const rustRow = [
+        ...sidebar.querySelectorAll<HTMLElement>(".sidebar-agent-menu__agent-switch"),
+      ].find((row) => row.textContent?.includes("rust-claw"));
+      expect(
+        rustRow?.querySelector(".agent-select__avatar--text")?.getAttribute("data-avatar"),
+      ).toBe("🦀");
+    });
+  });
+
   it("hydrates agents added while the switcher remains open", async () => {
     const request = vi.fn(async (_method: string, params: { agentId: string }) => ({
       agentId: params.agentId,