fix(chat): show tool identity in work logs

apps/mobile/src/lib/threadActivity.test.ts

@@ -291,6 +291,50 @@ function makeThread(
 }
 
 describe("buildThreadFeed", () => {
+  it("retains untitled tool identity through sparse lifecycle updates", () => {
+    const turnId = TurnId.make("untitled-turn");
+    const activities = ["tool.updated", "tool.updated", "tool.completed"].map((kind, index) =>
+      makeActivity({
+        id: EventId.make(`untitled-${index}`),
+        kind,
+        tone: "tool",
+        summary: kind === "tool.completed" ? "Tool" : "Tool updated",
+        createdAt: `2026-09-15T00:00:0${index}.000Z`,
+        turnId,
+        payload: {
+          itemType: "dynamic_tool_call",
+          toolCallId: "read-1",
+          ...(index === 0 ? { data: { toolName: "Read", kind: "read" } } : {}),
+        },
+      }),
+    );
+    for (let count = 1; count <= activities.length; count++) {
+      const [group] = buildThreadFeed(
+        makeThread({
+          id: ThreadId.make("untitled-tools"),
+          projectId: ProjectId.make("project-1"),
+          title: "Untitled tools",
+          activities: activities.slice(0, count),
+        }),
+      );
+      expect(group?.type).toBe("activity-group");
+      if (group?.type !== "activity-group") return;
+      expect(group.activities).toHaveLength(1);
+      expect(workEntryRowLabel(group.activities[0]!.workEntry)).toBe("Read file");
+      const rows = deriveThreadFeedPresentation(
+        [group],
+        {
+          turnId,
+          state: count < activities.length ? "running" : "completed",
+          startedAt: activities[0]!.createdAt,
+          completedAt: count < activities.length ? null : activities.at(-1)!.createdAt,
+        },
+        new Set([turnId]),
+      );
+      expect(rows.find((row) => row.type === "work-toggle")?.summary).toBe("Read file");
+    }
+  });
+
   it("reuses unchanged feed and presentation rows during an assistant text update", () => {
     const completedTurnId = TurnId.make("completed-turn");
     const activeTurnId = TurnId.make("active-turn");
@@ -579,7 +623,10 @@ describe("buildThreadFeed", () => {
     expect(row?.workEntry.detail).toBe(command);
     expect(row?.getFullDetail()).toBe(`${command}\n\n${command}`);
     expect(row?.canExpand).toBe(true);
-    expect(workEntryRowLabel(row!.workEntry, true)).toBe("Command");
+    expect(workEntryRowLabel(row!.workEntry, true)).toBe("Ran printf");
+    expect(workEntryRowLabel({ ...row!.workEntry, toolLifecycleStatus: "inProgress" }, true)).toBe(
+      "Running printf",
+    );
   });
 
   it.each([

apps/mobile/src/lib/threadActivity.ts

@@ -463,8 +463,8 @@ function toDerivedWorkLogEntry(activity: OrchestrationThreadActivity): DerivedWo
       : null;
   const commandPreview = extractToolCommand(payload);
   const changedFiles = extractChangedFiles(payload);
-  const title = extractToolTitle(payload);
-  const toolPresentation = extractToolActivityPresentation(payload);
+  const toolPresentation = extractToolActivityPresentation(payload, activity.summary);
+  const title = toolPresentation.toolTitle ?? null;
   // Terminal task updates carry identity so they replace each child's progress row.
   const isTaskActivity =
     activity.kind === "task.started" ||
@@ -1018,7 +1018,9 @@ export function workEntryRowLabel(entry: WorkLogEntry, expanded = false): string
   if (entry.agentSpawn) return agentSpawnLabel(entry.agentSpawn);
   const presentation = resolveWorkEntryToolPresentation(entry);
   if (presentation) return presentation.displayName;
-  if (expanded && entry.command?.trim()) return "Command";
+  if (expanded && entry.command?.trim()) {
+    return commandWorkEntryLabel(entry.command, entry.toolLifecycleStatus);
+  }
   const preview = workEntryPreview(entry);
   if (expanded) return preview?.trim() || workEntryHeading(entry);
   const compactPreview = preview === null ? null : collapseWhitespace(stripShellWrapper(preview));
@@ -1381,10 +1383,6 @@ function extractToolCommand(payload: Record<string, unknown> | null): {
   };
 }
 
-function extractToolTitle(payload: Record<string, unknown> | null): string | null {
-  return asTrimmedString(payload?.title);
-}
-
 function stripTrailingExitCode(value: string): {
   output: string | null;
   exitCode?: number | undefined;
@@ -2079,20 +2077,26 @@ function liveToolActivitySummary(activity: ThreadFeedActivity, presentTense: boo
   if (presentation) return presentation.displayName;
   const command = activity.workEntry.command?.trim();
   if (command) {
-    const program = commandProgramName(command);
-    const verb =
-      status === "inProgress"
-        ? "Running"
-        : status === "failed"
-          ? "Failed"
-          : status === "declined"
-            ? "Declined"
-            : status === "stopped"
-              ? "Stopped"
-              : "Ran";
-    return `${verb} ${program ?? "command"}`;
-  }
-  return activity.detail ?? activity.summary;
+    return commandWorkEntryLabel(command, status);
+  }
+  return workEntryRowLabel(activity.workEntry);
+}
+
+function commandWorkEntryLabel(
+  command: string,
+  status: WorkLogToolLifecycleStatus | undefined,
+): string {
+  const verb =
+    status === "inProgress"
+      ? "Running"
+      : status === "failed"
+        ? "Failed"
+        : status === "declined"
+          ? "Declined"
+          : status === "stopped"
+            ? "Stopped"
+            : "Ran";
+  return `${verb} ${commandProgramName(command) ?? "command"}`;
 }
 
 export function setPendingUserInputCustomAnswer(

apps/server/src/orchestration/ActivityPayloadProjection.test.ts

@@ -21,6 +21,63 @@ function activity(payload: Record<string, unknown>): OrchestrationThreadActivity
  * assertions are the tripwire.
  */
 describe("projectActivityPayload", () => {
+  it.each([
+    {
+      data: { toolName: "Read", input: { file_path: "/repo/app.ts" } },
+      title: "Read file",
+      detail: "/repo/app.ts",
+    },
+    {
+      data: { kind: "read", locations: [{ path: "/repo/app.ts" }] },
+      title: "Read file",
+      detail: "/repo/app.ts",
+    },
+    {
+      data: { tool: "grep", input: { pattern: "cleanup" } },
+      title: "Searched files",
+      detail: "cleanup",
+    },
+    {
+      data: { toolName: "WebSearch", input: { query: "React cleanup" } },
+      title: "Searched the web",
+      detail: "React cleanup",
+    },
+    {
+      data: { toolName: "Edit", input: { file_path: "/repo/app.ts" } },
+      title: "Changed files",
+      detail: "/repo/app.ts",
+    },
+    {
+      data: { item: { tool: "list_issues", server: "github" } },
+      title: "github.list_issues",
+      detail: undefined,
+    },
+  ])("retains untitled $title identity before slimming", ({ data, title, detail }) => {
+    const itemType = "item" in data ? "mcp_tool_call" : "dynamic_tool_call";
+    const source = activity({ itemType, data });
+    const projected = projectActivityPayload(source);
+    expect(projected.payload).toMatchObject({ title, ...(detail ? { detail } : {}) });
+    expect(source.payload).toEqual({ itemType, data });
+    expect(projectActivityPayload(projected)).toEqual(projected);
+  });
+
+  it("bounds inferred targets without replacing existing output or useful labels", () => {
+    const data = { toolName: "Read", input: { file_path: `/repo/${"a".repeat(1000)}.ts` } };
+    expect(
+      projectActivityPayload(activity({ itemType: "dynamic_tool_call", data })).payload,
+    ).toMatchObject({ title: "Read file", detail: data.input.file_path.slice(0, 180) });
+    expect(
+      projectActivityPayload(
+        activity({ itemType: "dynamic_tool_call", detail: "Permission denied", data }),
+      ).payload,
+    ).toMatchObject({ title: "Read file", detail: "Permission denied" });
+    expect(
+      projectActivityPayload(
+        activity({ itemType: "dynamic_tool_call", title: "Inspect config", data }),
+      ).payload,
+    ).toMatchObject({ title: "Inspect config" });
+  });
+
   it("preserves tool attribution (agentId/parentToolUseId) through data slimming", () => {
     const projected = projectActivityPayload(
       activity({

apps/server/src/orchestration/ActivityPayloadProjection.ts

@@ -1,4 +1,9 @@
-import { projectQuestionToolInput } from "@t3tools/shared/toolActivity";
+import {
+  deriveToolActivityPresentation,
+  isGenericToolLabel,
+  projectQuestionToolInput,
+} from "@t3tools/shared/toolActivity";
+import { isToolLifecycleItemType } from "@t3tools/contracts";
 import type {
   OrchestrationEvent,
   OrchestrationThreadActivity,
@@ -425,12 +430,30 @@ function projectAcpContent(value: unknown): Record<string, unknown> | undefined
 export function projectActivityPayload(
   activity: OrchestrationThreadActivity,
 ): OrchestrationThreadActivity {
-  const payload = asRecord(activity.payload);
+  let payload = asRecord(activity.payload);
   const data = asRecord(payload?.data);
   if (!payload || !data) {
     return activity;
   }
 
+  // Derive identity before slimming drops primary arguments, including historical rows.
+  if (
+    typeof payload.itemType === "string" &&
+    isToolLifecycleItemType(payload.itemType) &&
+    isGenericToolLabel(asTrimmedString(payload.title) ?? activity.summary)
+  ) {
+    const presentation = deriveToolActivityPresentation({ itemType: payload.itemType, data });
+    if (!isGenericToolLabel(presentation.summary)) {
+      payload = {
+        ...payload,
+        title: presentation.summary.slice(0, 180),
+        ...(!payload.detail && presentation.detail
+          ? { detail: presentation.detail.slice(0, 180) }
+          : {}),
+      };
+    }
+  }
+
   const itemStatus = asRecord(data.item)?.status;
   const statusPayload =
     payload.status === "completed" && (itemStatus === "failed" || itemStatus === "declined")

apps/web/src/session-logic.ts

@@ -550,8 +550,8 @@ function toDerivedWorkLogEntry(activity: OrchestrationThreadActivity): DerivedWo
       : null;
   const commandPreview = extractToolCommand(payload);
   const changedFiles = extractChangedFiles(payload);
-  const title = extractToolTitle(payload);
-  const toolPresentation = extractToolActivityPresentation(payload);
+  const toolPresentation = extractToolActivityPresentation(payload, activity.summary);
+  const title = toolPresentation.toolTitle ?? null;
   const isTaskActivity =
     activity.kind === "task.started" ||
     activity.kind === "task.progress" ||
@@ -1142,10 +1142,6 @@ function extractToolCommand(payload: Record<string, unknown> | null): {
   };
 }
 
-function extractToolTitle(payload: Record<string, unknown> | null): string | null {
-  return asTrimmedString(payload?.title);
-}
-
 function extractToolCallId(payload: Record<string, unknown> | null): string | null {
   const data = asRecord(payload?.data);
   return asTrimmedString(payload?.toolCallId) ?? asTrimmedString(data?.toolCallId);

packages/client-runtime/src/work-log/toolPresentation.test.ts

@@ -3,6 +3,15 @@ import { describe, expect, it } from "@effect/vitest";
 import { extractToolActivityPresentation } from "./toolPresentation.ts";
 
 describe("extractToolActivityPresentation", () => {
+  it("uses retained tool metadata without inventing identity for sparse updates", () => {
+    const payload = { itemType: "dynamic_tool_call", title: "Tool updated" };
+    expect(
+      extractToolActivityPresentation({ ...payload, data: { toolName: "Read" } }, "Tool updated"),
+    ).toEqual({ toolTitle: "Read file" });
+    expect(extractToolActivityPresentation(payload, "Tool updated")).toEqual({});
+    expect(extractToolActivityPresentation({ itemType: "web_search" }, "Web search")).toEqual({});
+  });
+
   it("reads provider-neutral presentation fields", () => {
     expect(
       extractToolActivityPresentation({

packages/client-runtime/src/work-log/toolPresentation.ts

@@ -4,8 +4,11 @@ import type {
   ToolActivitySource,
   ToolActivitySurface,
 } from "@t3tools/contracts";
+import { isToolLifecycleItemType } from "@t3tools/contracts";
+import { deriveToolActivityPresentation, isGenericToolLabel } from "@t3tools/shared/toolActivity";
 
 export interface ExtractedToolActivityPresentation {
+  readonly toolTitle?: string;
   readonly toolSurface?: ToolActivitySurface;
   readonly toolIcon?: ToolActivityIcon;
   readonly toolSource?: ToolActivitySource;
@@ -107,15 +110,25 @@ function activitySource(value: unknown): ToolActivitySource | undefined {
 
 export function extractToolActivityPresentation(
   payloadValue: unknown,
+  fallbackSummary?: string,
 ): ExtractedToolActivityPresentation {
   const payload = asRecord(payloadValue);
+  const title = typeof payload?.title === "string" ? payload.title.trim() : undefined;
+  const label = title || fallbackSummary;
+  const toolTitle =
+    isGenericToolLabel(label) &&
+    typeof payload?.itemType === "string" &&
+    isToolLifecycleItemType(payload.itemType)
+      ? deriveToolActivityPresentation({ itemType: payload.itemType, data: payload.data }).summary
+      : title;
   const toolSurface =
     payload?.toolSurface === "browser" || payload?.toolSurface === "computer"
       ? payload.toolSurface
       : undefined;
   const toolIcon = activityIcon(payload?.toolIcon);
   const toolSource = activitySource(payload?.toolSource);
   return {
+    ...(toolTitle && !isGenericToolLabel(toolTitle) ? { toolTitle } : {}),
     ...(toolSurface ? { toolSurface } : {}),
     ...(toolIcon ? { toolIcon } : {}),
     ...(toolSource ? { toolSource } : {}),

packages/shared/src/toolActivity.test.ts

@@ -3,6 +3,35 @@ import { describe, expect, it } from "vite-plus/test";
 import { deriveToolActivityPresentation } from "./toolActivity.ts";
 
 describe("toolActivity", () => {
+  it.each([
+    { data: { rawInput: {}, input: { query: " cleanup " } }, detail: "cleanup" },
+    {
+      data: {
+        rawInput: { query: " ", pattern: 42 },
+        input: { searchTerm: null },
+        item: { arguments: { pattern: " TODO " } },
+      },
+      detail: "TODO",
+    },
+    {
+      data: {
+        rawInput: { searchTerm: "raw" },
+        input: { query: "input" },
+        item: { arguments: { query: "item" } },
+      },
+      detail: "raw",
+    },
+    {
+      data: { rawInput: { query: "query", pattern: "pattern", searchTerm: "term" } },
+      detail: "query",
+    },
+  ])("uses the first valid search query ($detail)", ({ data, detail }) => {
+    expect(deriveToolActivityPresentation({ title: "Grep", data })).toEqual({
+      summary: "Searched files",
+      detail,
+    });
+  });
+
   it("normalizes command tools to a stable ran-command label", () => {
     expect(
       deriveToolActivityPresentation({