diff --git a/ui/src/components/task-chat/TaskChatLiveTail.test.tsx b/ui/src/components/task-chat/TaskChatLiveTail.test.tsx
index 8d205ee0b2e..c778abb2ab2 100644
--- a/ui/src/components/task-chat/TaskChatLiveTail.test.tsx
+++ b/ui/src/components/task-chat/TaskChatLiveTail.test.tsx
@@ -59,7 +59,7 @@ describe("TaskChatLiveTail", () => {
     expect(container.textContent).toContain("src/app.ts");
   });
 
-  it("renders a tool's diff inset", () => {
+  it("keeps tool diff bodies out of the activity feed", () => {
     const items = parse([
       { kind: "tool_call", ts: TS, name: "Edit", toolUseId: "t1", input: { file_path: "a.ts" } },
       { kind: "diff", ts: TS, changeType: "add", text: "const x = 1;" },
@@ -69,8 +69,16 @@ describe("TaskChatLiveTail", () => {
 
     const phaseSummary = container.querySelector<HTMLButtonElement>('[data-testid="task-chat-phase-summary"]');
     expect(phaseSummary?.getAttribute("aria-expanded")).toBe("true");
-    expect(container.textContent).toContain("const x = 1;");
+    expect(container.textContent).not.toContain("const x = 1;");
+    expect(container.textContent).not.toContain("+1 −1");
+
+    const tool = container.querySelector<HTMLButtonElement>(".tc-enter-tool button");
+    expect(tool).not.toBeNull();
+    flushSync(() => tool?.click());
+
     expect(container.textContent).toContain("+1 −1");
+    expect(container.textContent).not.toContain("const x = 1;");
+    expect(container.querySelector('[data-testid="task-chat-tool-change-summary"]')).not.toBeNull();
   });
 
   it("drops the debug plumbing kinds RunTranscriptView surfaced", () => {
diff --git a/ui/src/components/task-chat/TaskChatProtocolActivityRow.test.tsx b/ui/src/components/task-chat/TaskChatProtocolActivityRow.test.tsx
index 0c2e7a0ee8b..766c2e0db8d 100644
--- a/ui/src/components/task-chat/TaskChatProtocolActivityRow.test.tsx
+++ b/ui/src/components/task-chat/TaskChatProtocolActivityRow.test.tsx
@@ -33,7 +33,7 @@ describe("TaskChatProtocolActivityRow", () => {
     ));
   }
 
-  it("renders research as one compact line with expandable sources", () => {
+  it("renders long research results as a bounded readable list", () => {
     const item: TaskChatProviderActivityItem = {
       id: "research",
       kind: "protocol",
@@ -43,9 +43,17 @@ describe("TaskChatProtocolActivityRow", () => {
       status: "completed",
       title: "Research",
       summary: "smoked pork shoulder",
-      details: [{ label: "Query", value: "smoked pork shoulder", mono: true }],
+      details: [
+        { label: "Action", value: "search" },
+        { label: "Status", value: "completed" },
+        { label: "Query", value: "site:nextjs.org/docs/app/api-reference/config/eslint Next.js 16 eslint.config.mjs core-web-vitals typescript", mono: true },
+      ],
       steps: [],
-      links: [{ label: "Smoking guide", href: "https://example.com/smoking", description: "Temperature targets" }],
+      links: Array.from({ length: 6 }, (_, index) => ({
+        label: `Next.js configuration result ${index + 1}`,
+        href: `https://nextjs.org/docs/result-${index + 1}`,
+        description: "A long provider-authored snippet that stays on one compact line in the activity feed.",
+      })),
       children: [],
     };
     render(item);
@@ -62,10 +70,17 @@ describe("TaskChatProtocolActivityRow", () => {
     expect(row?.getAttribute("aria-expanded")).toBe("true");
     const detail = container.querySelector('[data-testid="task-chat-protocol-activity-detail"]');
     expect(detail?.id).toBe(row?.getAttribute("aria-controls"));
-    expect(detail?.textContent).toContain("Smoking guide");
+    expect(detail?.querySelector('[data-testid="task-chat-research-query"]')?.textContent).toContain("eslint.config.mjs");
+    expect(detail?.querySelectorAll('ol[aria-label="Research sources"] li')).toHaveLength(5);
+    expect(detail?.textContent).toContain("Show 1 more result");
+    expect(detail?.textContent).not.toContain("Actionsearch");
+
+    const showMore = Array.from(detail?.querySelectorAll("button") ?? []).find((button) => button.textContent?.includes("Show 1 more result"));
+    act(() => showMore?.click());
+    expect(detail?.querySelectorAll('ol[aria-label="Research sources"] li')).toHaveLength(6);
   });
 
-  it("keeps workspace files and diffs inside the row detail", () => {
+  it("summarizes workspace files without rendering inline diff bodies", () => {
     render({
       id: "workspace",
       kind: "protocol",
@@ -74,16 +89,26 @@ describe("TaskChatProtocolActivityRow", () => {
       revision: 1,
       source: "runner_verified",
       complete: true,
-      files: [{ path: "ui/src/App.tsx", operation: "modify", previousPath: null, additions: 1, deletions: 1, binary: false, diff: "-old\n+new" }],
-      totals: { files: 1, additions: 1, deletions: 1 },
+      files: Array.from({ length: 10 }, (_, index) => ({
+        path: `ui/src/file-${index + 1}.tsx`,
+        operation: "modify" as const,
+        previousPath: null,
+        additions: 1,
+        deletions: 1,
+        binary: false,
+        diff: `-old-${index + 1}\n+new-${index + 1}`,
+      })),
+      totals: { files: 10, additions: 10, deletions: 10 },
       patchArtifactRef: null,
     });
 
     const row = container.querySelector<HTMLButtonElement>('[data-testid="task-chat-protocol-activity-row"] button');
     expect(row?.textContent).toContain("Edited files");
     act(() => row?.click());
-    expect(container.textContent).toContain("ui/src/App.tsx");
-    expect(container.textContent).toContain("+new");
+    expect(container.textContent).toContain("ui/src/file-1.tsx");
+    expect(container.textContent).toContain("2 more files not shown");
+    expect(container.textContent).not.toContain("new-1");
+    expect(container.querySelector('[data-testid="task-chat-workspace-change-details"] pre')).toBeNull();
   });
 
   it("renders durable resources as direct compact links", () => {
diff --git a/ui/src/components/task-chat/TaskChatProtocolActivityRow.tsx b/ui/src/components/task-chat/TaskChatProtocolActivityRow.tsx
index 516c97f47b1..8608f269d52 100644
--- a/ui/src/components/task-chat/TaskChatProtocolActivityRow.tsx
+++ b/ui/src/components/task-chat/TaskChatProtocolActivityRow.tsx
@@ -11,6 +11,7 @@ import { MarkdownBody } from "@/components/MarkdownBody";
 import { WorkspaceFileLink } from "@/components/WorkspaceFileLink";
 import { cn } from "@/lib/utils";
 import type {
+  TaskChatProtocolDetail,
   TaskChatProtocolItem,
   TaskChatProtocolStep,
   TaskChatProviderActivityItem,
@@ -23,6 +24,9 @@ import {
   protocolActivityPresentation,
 } from "./task-chat-activity-presentation";
 
+const COMPACT_RESEARCH_RESULT_LIMIT = 5;
+const COMPACT_WORKSPACE_FILE_LIMIT = 8;
+
 function StatusIcon({ status }: { status: "running" | "completed" | "failed" | "interrupted" | "informational" }) {
   if (status === "running") return <Loader2 className="h-3.5 w-3.5 animate-spin text-(--status-agent-running)" aria-hidden />;
   if (status === "failed" || status === "interrupted") return <X className="h-3.5 w-3.5 text-destructive" aria-hidden />;
@@ -37,7 +41,91 @@ function stepStatusIcon(status: TaskChatProtocolStep["status"]) {
   return <Circle className="h-3 w-3 text-muted-foreground" aria-hidden />;
 }
 
+function DetailList({ details }: { details: readonly TaskChatProtocolDetail[] }) {
+  if (details.length === 0) return null;
+  return (
+    <dl className="flex min-w-0 flex-col gap-1.5" data-testid="task-chat-provider-detail-list">
+      {details.map((detail) => (
+        <div className="grid min-w-0 grid-cols-1 gap-0.5 sm:grid-cols-(--gtc-task-chat-details) sm:gap-3" key={`${detail.label}:${detail.value}`}>
+          <dt className="text-muted-foreground">{detail.label}</dt>
+          <dd className={cn("min-w-0 break-words text-foreground", detail.mono && "font-mono")}>{detail.value}</dd>
+        </div>
+      ))}
+    </dl>
+  );
+}
+
+function sourceHostname(href: string): string {
+  try {
+    return new URL(href).hostname.replace(/^www\./, "");
+  } catch {
+    return href;
+  }
+}
+
+function ResearchDetails({ item }: { item: TaskChatProviderActivityItem }) {
+  const [showAllResults, setShowAllResults] = useState(false);
+  const query = item.details.find((detail) => detail.label.toLowerCase() === "query");
+  const additionalDetails = item.details.filter((detail) => !["action", "query", "status"].includes(detail.label.toLowerCase()));
+  const visibleLinks = showAllResults ? item.links : item.links.slice(0, COMPACT_RESEARCH_RESULT_LIMIT);
+  const hiddenResultCount = item.links.length - visibleLinks.length;
+
+  return (
+    <div className="flex min-w-0 flex-col gap-2.5">
+      {query ? (
+        <div className="min-w-0 rounded-sm bg-muted/40 px-2.5 py-2" data-testid="task-chat-research-query">
+          <p className="text-(length:--text-nano) font-medium uppercase tracking-wide text-muted-foreground">Query</p>
+          <p className="mt-0.5 min-w-0 break-words font-mono text-(length:--text-micro) text-foreground">{query.value}</p>
+        </div>
+      ) : null}
+      {item.links.length > 0 ? (
+        <div className="min-w-0">
+          <p className="mb-1 text-(length:--text-nano) font-medium uppercase tracking-wide text-muted-foreground">
+            {item.links.length} {item.links.length === 1 ? "result" : "results"}
+          </p>
+          <ol className="divide-y divide-border/60" aria-label="Research sources">
+            {visibleLinks.map((link, index) => (
+              <li className="min-w-0 py-1.5 first:pt-0 last:pb-0" key={`${link.href}:${index}`}>
+                <a className="flex min-w-0 items-center gap-1 font-medium text-foreground hover:underline" href={link.href} target="_blank" rel="noreferrer">
+                  <span className="truncate">{link.label}</span>
+                  <ExternalLink className="h-3 w-3 shrink-0" aria-hidden />
+                </a>
+                <p className="mt-0.5 flex min-w-0 gap-2 text-muted-foreground">
+                  <span className="shrink-0">{sourceHostname(link.href)}</span>
+                  {link.description ? <span className="min-w-0 truncate">{link.description}</span> : null}
+                </p>
+              </li>
+            ))}
+          </ol>
+          {hiddenResultCount > 0 ? (
+            <button
+              type="button"
+              className="mt-1.5 text-muted-foreground hover:text-foreground"
+              onClick={() => setShowAllResults(true)}
+            >
+              Show {hiddenResultCount} more {hiddenResultCount === 1 ? "result" : "results"}
+            </button>
+          ) : showAllResults && item.links.length > COMPACT_RESEARCH_RESULT_LIMIT ? (
+            <button
+              type="button"
+              className="mt-1.5 text-muted-foreground hover:text-foreground"
+              onClick={() => setShowAllResults(false)}
+            >
+              Show fewer results
+            </button>
+          ) : null}
+        </div>
+      ) : null}
+      <DetailList details={additionalDetails} />
+      {item.output || item.outputTruncated ? (
+        <p className="text-muted-foreground">Additional provider output is available in Runner Inspector.</p>
+      ) : null}
+    </div>
+  );
+}
+
 function ProviderDetails({ item }: { item: TaskChatProviderActivityItem }) {
+  if (item.family === "research") return <ResearchDetails item={item} />;
   return (
     <div className="flex min-w-0 flex-col gap-2">
       {item.steps.length > 0 ? (
@@ -78,14 +166,7 @@ function ProviderDetails({ item }: { item: TaskChatProviderActivityItem }) {
         </ul>
       ) : null}
       {item.details.length > 0 ? (
-        <dl className="grid gap-x-3 gap-y-1 sm:grid-cols-(--gtc-2)">
-          {item.details.map((detail) => (
-            <div className="contents" key={`${detail.label}:${detail.value}`}>
-              <dt className="text-muted-foreground">{detail.label}</dt>
-              <dd className={cn("min-w-0 break-words text-foreground", detail.mono && "font-mono")}>{detail.value}</dd>
-            </div>
-          ))}
-        </dl>
+        <DetailList details={item.details} />
       ) : null}
       {item.output ? (
         <pre className="max-h-(--sz-64) overflow-auto whitespace-pre-wrap rounded-sm bg-muted/50 p-2 font-mono text-(length:--text-micro) text-foreground">{item.output}</pre>
@@ -96,12 +177,15 @@ function ProviderDetails({ item }: { item: TaskChatProviderActivityItem }) {
 }
 
 function WorkspaceChangeDetails({ item }: { item: TaskChatWorkspaceChangeItem }) {
-  return item.files.length > 0 ? (
-    <ul className="flex min-w-0 flex-col gap-2" aria-label="Changed files">
-      {item.files.map((file) => (
-        <li className="flex min-w-0 flex-col gap-1" key={`${file.operation}:${file.path}`}>
-          <span className="flex min-w-0 items-center gap-2">
-            <span className="min-w-0 flex-1 truncate font-mono text-foreground">
+  if (item.files.length === 0) return <p className="text-muted-foreground">No changed-file details were reported.</p>;
+  const visibleFiles = item.files.slice(0, COMPACT_WORKSPACE_FILE_LIMIT);
+  const hiddenFileCount = item.files.length - visibleFiles.length;
+  return (
+    <div className="min-w-0" data-testid="task-chat-workspace-change-details">
+      <ul className="flex min-w-0 flex-col divide-y divide-border/60" aria-label="Changed files">
+        {visibleFiles.map((file) => (
+          <li className="flex min-w-0 items-center gap-2 py-1.5 first:pt-0 last:pb-0" key={`${file.operation}:${file.path}`}>
+            <span className="min-w-0 flex-1 truncate font-mono text-foreground" title={file.previousPath ? `${file.previousPath} → ${file.path}` : file.path}>
               {file.previousPath ? `${file.previousPath} → ${file.path}` : file.path}
             </span>
             <span className="shrink-0 capitalize text-muted-foreground">{file.operation.replaceAll("_", " ")}</span>
@@ -110,12 +194,12 @@ function WorkspaceChangeDetails({ item }: { item: TaskChatWorkspaceChangeItem })
                 {file.additions == null ? "" : `+${file.additions}`} {file.deletions == null ? "" : `−${file.deletions}`}
               </span>
             ) : null}
-          </span>
-          {file.diff ? <pre className="max-h-(--sz-64) overflow-auto whitespace-pre-wrap rounded-sm bg-muted/50 p-2 font-mono text-(length:--text-micro) text-foreground">{file.diff}</pre> : null}
-        </li>
-      ))}
-    </ul>
-  ) : <p className="text-muted-foreground">No changed-file details were reported.</p>;
+          </li>
+        ))}
+      </ul>
+      {hiddenFileCount > 0 ? <p className="mt-1.5 text-muted-foreground">{hiddenFileCount} more {hiddenFileCount === 1 ? "file" : "files"} not shown</p> : null}
+    </div>
+  );
 }
 
 function WorkspaceFileDetails({ item }: { item: TaskChatWorkspaceFileItem }) {
diff --git a/ui/src/components/task-chat/TaskChatProtocolCard.tsx b/ui/src/components/task-chat/TaskChatProtocolCard.tsx
index b3244e7a847..28854fa0eb9 100644
--- a/ui/src/components/task-chat/TaskChatProtocolCard.tsx
+++ b/ui/src/components/task-chat/TaskChatProtocolCard.tsx
@@ -167,9 +167,9 @@ function ProviderActivityCard({ item }: { item: TaskChatProviderActivityItem })
             <ChevronDown aria-hidden className="h-3.5 w-3.5" /> Details
           </summary>
           {item.details.length > 0 ? (
-            <dl className="mt-2 grid gap-x-3 gap-y-1 text-xs sm:grid-cols-(--gtc-2)">
+            <dl className="mt-2 flex min-w-0 flex-col gap-1.5 text-xs">
               {item.details.map((detail) => (
-                <div key={`${detail.label}:${detail.value}`} className="contents">
+                <div key={`${detail.label}:${detail.value}`} className="grid min-w-0 grid-cols-1 gap-0.5 sm:grid-cols-(--gtc-task-chat-details) sm:gap-3">
                   <dt className="text-muted-foreground">{detail.label}</dt>
                   <dd className={cn("min-w-0 break-words text-foreground", detail.mono && "font-mono")}>{detail.value}</dd>
                 </div>
diff --git a/ui/src/components/task-chat/TaskChatToolCard.tsx b/ui/src/components/task-chat/TaskChatToolCard.tsx
index 13b4fe311ff..62211ed588d 100644
--- a/ui/src/components/task-chat/TaskChatToolCard.tsx
+++ b/ui/src/components/task-chat/TaskChatToolCard.tsx
@@ -21,14 +21,14 @@ const STATUS_ICON = {
 /**
  * Tool invocation as a flat activity row (v7): [glyph] [name] [mono target] …
  * [hover chevron] [status]. No card chrome — activity is metadata, not
- * content. Clicking toggles the mono result/detail block (left-rail inset);
- * diffs render as an inset panel below the row.
+ * content. Clicking toggles a compact result/change summary (left-rail
+ * inset). Full diff bodies stay out of the activity feed.
  */
 export function TaskChatToolCard({ item }: { item: TaskChatToolItem }) {
   const { Icon, spin, tone } = STATUS_ICON[item.status];
   const RowIcon = toolTaxonomy(item.rawName ?? item.name).icon;
   const [showDetail, setShowDetail] = useState(false);
-  const expandable = Boolean(item.detail);
+  const expandable = Boolean(item.detail || item.diff);
 
   return (
     <div className="tc-enter-tool flex flex-col text-xs">
@@ -70,35 +70,20 @@ export function TaskChatToolCard({ item }: { item: TaskChatToolItem }) {
           <Icon className={cn("h-3.5 w-3.5", tone, spin && "animate-spin")} aria-hidden />
         </span>
       </button>
-      {expandable && showDetail ? (
+      {item.detail && showDetail ? (
         <pre className="ml-2.5 mt-0.5 overflow-x-auto whitespace-pre-wrap border-l-2 border-border py-1 pl-2.5 font-mono text-(length:--text-micro) leading-relaxed text-muted-foreground">
           {item.detail}
         </pre>
       ) : null}
-      {item.diff ? (
-        <div className="tc-reveal-diff ml-2.5 mt-1 border-l-2 border-border pl-2.5">
-          <div className="mb-1 flex items-center gap-2 text-(length:--text-micro) text-muted-foreground">
-            {item.diff.path ? <span className="truncate font-mono">{item.diff.path}</span> : null}
-            <span className="ml-auto shrink-0 font-mono font-semibold">
+      {item.diff && showDetail ? (
+        <div className="ml-2.5 mt-0.5 border-l-2 border-border py-1 pl-2.5" data-testid="task-chat-tool-change-summary">
+          <div className="flex min-w-0 items-center gap-2 text-(length:--text-micro) text-muted-foreground">
+            <span className="shrink-0">Changed</span>
+            {item.diff.path ? <span className="min-w-0 truncate font-mono text-foreground">{item.diff.path}</span> : null}
+            <span className="ml-auto shrink-0 font-mono">
               +{item.diff.added} −{item.diff.removed}
             </span>
           </div>
-          {item.diff.lines?.length ? (
-            <pre className="overflow-x-auto rounded-sm bg-muted/50 p-2 text-(length:--text-micro) leading-relaxed">
-              {item.diff.lines.map((l, i) => (
-                <div
-                  key={i}
-                  className={cn(
-                    l.kind === "add" && "text-(--status-task-icon-done)",
-                    l.kind === "remove" && "text-destructive",
-                    l.kind === "context" && "text-muted-foreground",
-                  )}
-                >
-                  {l.kind === "add" ? "+" : l.kind === "remove" ? "−" : " "} {l.text}
-                </div>
-              ))}
-            </pre>
-          ) : null}
         </div>
       ) : null}
     </div>
diff --git a/ui/src/index.css b/ui/src/index.css
index 05f0f8b0a47..933ce2cc4d9 100644
--- a/ui/src/index.css
+++ b/ui/src/index.css
@@ -2291,6 +2291,7 @@ span.paperclip-mention-chip[data-mention-kind="external-object"] {
 :root {
   --gtc-1: 56px 56px 24px minmax(0,1fr); /* Extracted from ui/src/components/DocumentDiffModal.tsx (grid-cols-[56px_56px_24px_minmax(0,1fr)]). */
   --gtc-case-revisions: 16rem 1fr; /* Extracted from ui/src/components/CaseRevisionRail.tsx (grid-cols-[16rem_1fr]). */
+  --gtc-task-chat-details: 6rem minmax(0,1fr);
   --gtc-2: auto minmax(0,1fr) 2.25rem; /* Extracted from ui/src/components/FileTree.tsx (grid-cols-[auto_minmax(0,1fr)_2.25rem]). */
   --gtc-3: minmax(0,1fr) 2.25rem; /* Extracted from ui/src/components/FileTree.tsx (grid-cols-[minmax(0,1fr)_2.25rem]). */
   --gtc-4: minmax(0,1fr); /* Extracted from ui/src/components/FileTree.tsx (grid-cols-[minmax(0,1fr)]). */
diff --git a/ui/storybook/stories/task-runner-protocol.stories.tsx b/ui/storybook/stories/task-runner-protocol.stories.tsx
index a82a7f7d93d..cbdf987ac99 100644
--- a/ui/storybook/stories/task-runner-protocol.stories.tsx
+++ b/ui/storybook/stories/task-runner-protocol.stories.tsx
@@ -234,6 +234,40 @@ const allProviderActivity: TaskChatItem[] = [
   providerActivity("provider_notice", "provider.notice.recorded", "informational", { summary: "Throughput temporarily reduced" }),
 ];
 
+const searchResultsAndFileChanges: TaskChatItem[] = [
+  providerActivity("research", "research.completed", "completed", {
+    summary: "site:nextjs.org/docs/app/api-reference/config/eslint Next.js 16 eslint.config.mjs core-web-vitals typescript",
+    details: [
+      { label: "Action", value: "search" },
+      { label: "Status", value: "completed" },
+      { label: "Query", value: "site:nextjs.org/docs/app/api-reference/config/eslint Next.js 16 eslint.config.mjs core-web-vitals typescript", mono: true },
+    ],
+    links: [
+      { label: "Configuration: ESLint | Next.js", href: "https://nextjs.org/docs/app/api-reference/config/eslint", description: "Configure ESLint in the App Router and understand the current defaults." },
+      { label: "next.config.js: eslint | Next.js", href: "https://nextjs.org/docs/pages/api-reference/config/next-config-js/eslint", description: "Legacy configuration behavior and migration notes." },
+      { label: "Configuration: TypeScript | Next.js", href: "https://nextjs.org/docs/app/api-reference/config/typescript", description: "TypeScript configuration options for modern Next.js applications." },
+      { label: "Upgrading: Codemods | Next.js", href: "https://nextjs.org/docs/app/guides/upgrading/codemods", description: "Automated migrations for eslint.config.mjs and current conventions." },
+      { label: "API Reference: Configuration | Next.js", href: "https://nextjs.org/docs/app/api-reference/config", description: "The complete application configuration reference." },
+      { label: "Next.js 16 upgrade guide", href: "https://nextjs.org/docs/app/guides/upgrading/version-16", description: "Breaking changes and recommended upgrade steps for version 16." },
+      { label: "Core Web Vitals", href: "https://nextjs.org/docs/app/api-reference/functions/use-report-web-vitals", description: "Measure and report application performance metrics." },
+    ],
+  }),
+  {
+    id: "file-change-search-story",
+    kind: "tool",
+    name: "File change",
+    rawName: "file_change",
+    target: "/Users/runner/workspaces/example/tsconfig.json",
+    status: "completed",
+    diff: {
+      path: "tsconfig.json",
+      added: 228,
+      removed: 0,
+      lines: Array.from({ length: 24 }, (_, index) => ({ kind: "add" as const, text: `generated diff line ${index + 1}` })),
+    },
+  },
+];
+
 function RunnerTransitionStory() {
   const [phase, setPhase] = useState(0);
   const items: TaskChatItem[] = phase === 0
@@ -454,6 +488,28 @@ export const RunnerLiveAllProviderFamilies: Story = {
   },
 };
 
+export const RunnerLiveSearchResultsAndFileChanges: Story = {
+  name: "Runner Activity / Live / Search Results and File Changes",
+  render: () => <RunnerTurnStory items={searchResultsAndFileChanges} />,
+  play: async ({ canvasElement }) => {
+    const canvas = within(canvasElement);
+    await userEvent.click(canvas.getByRole("button", { name: /expand run activity/i }));
+    const list = canvas.getByTestId("task-chat-runner-activity-list");
+    const researchRow = list.querySelector<HTMLElement>('[data-activity-family="research"]');
+    if (!researchRow) throw new Error("Research activity row did not render");
+    await userEvent.click(within(researchRow).getByRole("button"));
+    const toolRow = Array.from(list.querySelectorAll<HTMLElement>(".tc-enter-tool")).find((row) => row.textContent?.includes("File change"));
+    if (!toolRow) throw new Error("File change tool row did not render");
+    await userEvent.click(within(toolRow).getByRole("button"));
+
+    await expect(canvas.getByTestId("task-chat-research-query")).toHaveTextContent("eslint.config.mjs");
+    await expect(canvas.getByRole("list", { name: "Research sources" }).querySelectorAll("li")).toHaveLength(5);
+    await expect(canvas.getByText("Show 2 more results")).toBeVisible();
+    await expect(canvas.getByTestId("task-chat-tool-change-summary")).toHaveTextContent("+228 −0");
+    await expect(canvas.queryByText("generated diff line 1")).not.toBeInTheDocument();
+  },
+};
+
 export const RunnerLiveCommentaryAndStreamingUpdates: Story = {
   name: "Runner Activity / Live / Commentary and Streaming Updates",
   render: () => <RunnerTurnStory items={mixedLiveActivity} />,