Merge pull request #2041 from modelcontextprotocol/v2/fix/2001-duplicate-tool-selection

fix(web): key tool selection by row identity so duplicate tool names are individually inspectable

clients/web/src/App.test.tsx

@@ -363,7 +363,7 @@ vi.mock("./components/views/InspectorView/InspectorView", () => ({
   InspectorView: (props: {
     toolCallState?: { status?: string };
     toolsUi?: {
-      selectedToolName?: string;
+      selectedToolKey?: string;
       formValues: Record<string, unknown>;
       search: string;
     };
@@ -384,7 +384,7 @@ vi.mock("./components/views/InspectorView/InspectorView", () => ({
     onConnectionInfo: () => void;
     onToggleConnection: (id: string) => void;
     onToolsUiChange: (next: {
-      selectedToolName?: string;
+      selectedToolKey?: string;
       formValues: Record<string, unknown>;
       search: string;
     }) => void;
@@ -433,7 +433,7 @@ vi.mock("./components/views/InspectorView/InspectorView", () => ({
         {Object.keys(props.progressByTaskId ?? {}).join(",") || "none"}
       </span>
       <span data-testid="selected-tool">
-        {props.toolsUi?.selectedToolName ?? "none"}
+        {props.toolsUi?.selectedToolKey ?? "none"}
       </span>
       <span data-testid="tool-search">{props.toolsUi?.search || "none"}</span>
       <span data-testid="selected-prompt">
@@ -469,7 +469,7 @@ vi.mock("./components/views/InspectorView/InspectorView", () => ({
             formValues: {},
             search: "",
             ...props.toolsUi,
-            selectedToolName: "get_acts",
+            selectedToolKey: "0:get_acts",
           })
         }
       >
@@ -481,7 +481,7 @@ vi.mock("./components/views/InspectorView/InspectorView", () => ({
             formValues: {},
             search: "",
             ...props.toolsUi,
-            selectedToolName: "other_tool",
+            selectedToolKey: "1:other_tool",
           })
         }
       >
@@ -869,7 +869,7 @@ describe("App session-scoped state reset on disconnect", () => {
       expect(screen.getByTestId("tool-status")).toHaveTextContent("ok"),
     );
 
-    // A search keystroke leaves `selectedToolName` unchanged, so the result
+    // A search keystroke leaves `selectedToolKey` unchanged, so the result
     // stays put.
     await user.click(screen.getByText("set-tool-search"));
     await waitFor(() =>

clients/web/src/App.tsx

@@ -3160,17 +3160,17 @@ function App() {
   // drops the previous tool's result — the result panel renders `toolCallState`
   // regardless of selection, so without this a stale result would linger under
   // the newly-selected tool (which has no result of its own yet). Search and
-  // form edits keep `selectedToolName` unchanged, so they leave the result be.
+  // form edits keep `selectedToolKey` unchanged, so they leave the result be.
-  // Depends on `selectedToolName` only (not the whole `toolsUi`), so a search
+  // Depends on `selectedToolKey` only (not the whole `toolsUi`), so a search
   // keystroke doesn't churn the callback identity.
   const onToolsUiChange = useCallback(
     (next: ToolsUiState) => {
-      if (next.selectedToolName !== toolsUi.selectedToolName) {
+      if (next.selectedToolKey !== toolsUi.selectedToolKey) {
         setToolCallState(undefined);
       }
       setToolsUi(next);
     },
-    [toolsUi.selectedToolName],
+    [toolsUi.selectedToolKey],
   );
 
   // --- MCP Apps handlers. Unlike onCallTool (which feeds the Tools panel),

clients/web/src/components/groups/ToolControls/ToolControls.stories.tsx

@@ -45,7 +45,8 @@ export const Default: Story = {
 export const WithSelection: Story = {
   args: {
     tools: longToolList,
-    selectedName: "query_database",
+    // Row identity is `index:name`, so the selection names the position too.
+    selectedKey: "1:query_database",
   },
 };
 

clients/web/src/components/groups/ToolControls/ToolControls.test.tsx

@@ -83,7 +83,7 @@ describe("ToolControls", () => {
       <ToolControls {...baseProps} onSelectTool={onSelectTool} />,
     );
     await user.click(screen.getByText("git_status"));
-    expect(onSelectTool).toHaveBeenCalledWith("git_status");
+    expect(onSelectTool).toHaveBeenCalledWith("2:git_status");
   });
 
   it("does not invoke onSelectTool when the already-selected tool is clicked", async () => {
@@ -92,7 +92,7 @@ describe("ToolControls", () => {
     renderWithMantine(
       <ToolControls
         {...baseProps}
-        selectedName="git_status"
+        selectedKey="2:git_status"
         onSelectTool={onSelectTool}
       />,
     );
@@ -100,6 +100,40 @@ describe("ToolControls", () => {
     expect(onSelectTool).not.toHaveBeenCalled();
   });
 
+  it("selects each copy of a duplicated tool name independently", async () => {
+    // A `tools/list` may repeat a name. Selection is keyed by row identity, so
+    // selecting the first copy must leave the second clickable and unhighlighted
+    // (#2001 — with a name-keyed selection both highlighted and neither of the
+    // later copies could be opened).
+    const user = userEvent.setup();
+    const onSelectTool = vi.fn();
+    const duplicated: Tool[] = [
+      { name: "get_weather", inputSchema: { type: "object" } },
+      { name: "echo", inputSchema: { type: "object" } },
+      { name: "get_weather", inputSchema: { type: "object" } },
+    ];
+    renderWithMantine(
+      <ToolControls
+        {...baseProps}
+        tools={duplicated}
+        selectedKey="0:get_weather"
+        onSelectTool={onSelectTool}
+      />,
+    );
+    const rows = screen.getAllByText("get_weather");
+    expect(rows).toHaveLength(2);
+    // Only the selected row carries the highlight background.
+    const highlighted = rows
+      .map((row) => row.closest("button"))
+      .filter((button) => button?.style.background !== "");
+    expect(highlighted).toHaveLength(1);
+    expect(highlighted[0]).toBe(rows[0]?.closest("button"));
+
+    // The second copy is still clickable, and reports its own row key.
+    await user.click(rows[1] as HTMLElement);
+    expect(onSelectTool).toHaveBeenCalledWith("2:get_weather");
+  });
+
   it("does not show the list-changed indicator when listChanged is false", () => {
     renderWithMantine(<ToolControls {...baseProps} />);
     expect(screen.queryByText("List updated")).not.toBeInTheDocument();

clients/web/src/components/groups/ToolControls/ToolControls.tsx

@@ -23,13 +23,19 @@ import {
 } from "../../elements/ListPaginationControls/ListPaginationControls";
 import { ToolListItem } from "../ToolListItem/ToolListItem";
 import { useScrollMemory } from "../../../hooks/useScrollMemory";
+import { toolRowKey } from "../../../utils/toolUtils";
 
 export interface ToolControlsProps {
   tools: Tool[];
   /** Tools the SDK excluded from `tools/list` for invalid `x-mcp-header`
    * annotations (SEP-2243), shown below the list with the reason (#1632). */
   excludedTools?: ExcludedTool[];
-  selectedName?: string;
+  /**
+   * The selected row's {@link toolRowKey}, not its name — a `tools/list` may
+   * repeat a name, and a name-keyed selection would highlight every copy at
+   * once and make the others unclickable (#2001).
+   */
+  selectedKey?: string;
   // Search text is controlled by the parent (App, via ToolsScreen) so it
   // persists across tab navigation within a live session — see #1417.
   searchText?: string;
@@ -49,7 +55,8 @@ export interface ToolControlsProps {
   /** Pagination controls (#1721). */
   pagination: ListPaginationControlsProps;
   onSearchChange: (value: string) => void;
-  onSelectTool: (name: string) => void;
+  /** Emits the clicked row's {@link toolRowKey} (see `selectedKey`). */
+  onSelectTool: (key: string) => void;
 }
 
 // One excluded tool: a warning icon, the tool name (struck through, since it is
@@ -116,12 +123,12 @@ const ExcludedTooltip = Tooltip.withProps({
   position: "right",
 });
 
-// A server may return the same tool name more than once, so the name alone is
+// Excluded rows render into the same `Stack` as the list rows above them, so
-// not a unique React key — colliding keys let a filtered-out row survive
+// their keys share one namespace — and an excluded tool's index is counted
-// reconciliation instead of unmounting (#1957). The tool's position in the
+// within its own list, which would collide with a listed tool of the same name
-// unfiltered list disambiguates duplicates and stays stable while the search
+// at the same index. The prefix keeps the two spaces apart.
-// narrows, since it is captured before filtering.
+const excludedRowKey = (name: string, sourceIndex: number) =>
-const rowKey = (name: string, sourceIndex: number) => `${sourceIndex}:${name}`;
+  `excluded:${toolRowKey(name, sourceIndex)}`;
 
 /** Matches a tool against the (already lower-cased) search query by name or title. */
 const matchesQuery = (tool: Tool, query: string) =>
@@ -131,7 +138,7 @@ const matchesQuery = (tool: Tool, query: string) =>
 export function ToolControls({
   tools,
   excludedTools = [],
-  selectedName,
+  selectedKey,
   searchText = "",
   listChanged,
   onRefreshList,
@@ -146,14 +153,17 @@ export function ToolControls({
   // Stamp each row's source position before filtering, so the key survives the
   // list narrowing (#1957).
   const filteredTools = tools
-    .map((tool, sourceIndex) => ({ tool, key: rowKey(tool.name, sourceIndex) }))
+    .map((tool, sourceIndex) => ({
+      tool,
+      key: toolRowKey(tool.name, sourceIndex),
+    }))
     .filter(({ tool }) => !searchText || matchesQuery(tool, query));
   // Excluded tools are searchable too, matching name AND title like the main
   // list above, so a filtered view stays consistent.
   const filteredExcluded = excludedTools
     .map((excluded, sourceIndex) => ({
       ...excluded,
-      key: rowKey(excluded.tool.name, sourceIndex),
+      key: excludedRowKey(excluded.tool.name, sourceIndex),
     }))
     .filter(({ tool }) => !searchText || matchesQuery(tool, query));
 
@@ -183,9 +193,9 @@ export function ToolControls({
             <ToolListItem
               key={key}
               tool={tool}
-              selected={tool.name === selectedName}
+              selected={key === selectedKey}
               onClick={() => {
-                if (tool.name !== selectedName) onSelectTool(tool.name);
+                if (key !== selectedKey) onSelectTool(key);
               }}
             />
           ))}

clients/web/src/components/screens/ToolsScreen/ToolsScreen.test.tsx

@@ -82,6 +82,46 @@ describe("ToolsScreen", () => {
     ).not.toBeInTheDocument();
   });
 
+  it("opens the second copy of a duplicated tool name and calls it by its protocol name", async () => {
+    // A `tools/list` may repeat a name with a different schema. Selection is
+    // keyed by row identity, so the later copy is reachable and the detail
+    // panel shows *its* schema — a name-based lookup always resolved the first
+    // (#2001). The wire identity stays the duplicated name.
+    const user = userEvent.setup();
+    const onCallTool = vi.fn();
+    const duplicated: Tool[] = [
+      {
+        name: "get_weather",
+        inputSchema: {
+          type: "object",
+          properties: { city: { type: "string" } },
+        },
+      },
+      {
+        name: "get_weather",
+        inputSchema: {
+          type: "object",
+          properties: { zip: { type: "string", default: "94103" } },
+        },
+      },
+    ];
+    renderWithMantine(
+      <ControlledToolsScreen tools={duplicated} onCallTool={onCallTool} />,
+    );
+    const rows = screen.getAllByText("get_weather");
+    await user.click(rows[1] as HTMLElement);
+    // The second copy's own field renders — the first copy's does not.
+    expect(screen.getByLabelText(/zip/i)).toBeInTheDocument();
+    expect(screen.queryByLabelText(/city/i)).toBeNull();
+
+    await user.click(screen.getByRole("button", { name: /Execute/ }));
+    expect(onCallTool).toHaveBeenCalledWith(
+      "get_weather",
+      { zip: "94103" },
+      false,
+    );
+  });
+
   it("filters the sidebar list as the search text changes", async () => {
     const user = userEvent.setup();
     renderWithMantine(<ControlledToolsScreen />);
@@ -111,7 +151,7 @@ describe("ToolsScreen", () => {
     renderWithMantine(
       <ToolsScreen
         {...baseProps}
-        ui={{ ...EMPTY_TOOLS_UI, selectedToolName: "alpha" }}
+        ui={{ ...EMPTY_TOOLS_UI, selectedToolKey: "0:alpha" }}
         callState={{
           status: "ok",
           result: { content: [{ type: "text", text: "ok" }] },
@@ -134,7 +174,7 @@ describe("ToolsScreen", () => {
     function Host() {
       const [ui, setUi] = useState<ToolsUiState>({
         ...EMPTY_TOOLS_UI,
-        selectedToolName: "alpha",
+        selectedToolKey: "0:alpha",
       });
       const [callState, setCallState] = useState<ToolsScreenProps["callState"]>(
         {
@@ -264,7 +304,7 @@ describe("ToolsScreen", () => {
     renderWithMantine(
       <ToolsScreen
         {...baseProps}
-        ui={{ ...EMPTY_TOOLS_UI, selectedToolName: "alpha" }}
+        ui={{ ...EMPTY_TOOLS_UI, selectedToolKey: "0:alpha" }}
         callState={{ status: "pending" }}
       />,
     );
@@ -277,7 +317,7 @@ describe("ToolsScreen", () => {
     renderWithMantine(
       <ToolsScreen
         {...baseProps}
-        ui={{ ...EMPTY_TOOLS_UI, selectedToolName: "alpha" }}
+        ui={{ ...EMPTY_TOOLS_UI, selectedToolKey: "0:alpha" }}
         onCancelCall={onCancelCall}
         callState={{ status: "pending" }}
       />,

clients/web/src/components/screens/ToolsScreen/ToolsScreen.tsx

@@ -16,6 +16,7 @@ import { ToolResultPanel } from "../../groups/ToolResultPanel/ToolResultPanel";
 import { ToolCallErrorPanel } from "../../groups/ToolResultPanel/ToolCallErrorPanel";
 import { resultHasResourceLinks } from "../../groups/ToolResultPanel/toolResultUtils";
 import { collectSchemaDefaults, toFormSchema } from "../../../utils/jsonUtils";
+import { findToolByRowKey } from "../../../utils/toolUtils";
 
 export interface ToolCallState {
   status: "idle" | "pending" | "ok" | "error";
@@ -35,7 +36,14 @@ export interface ToolCallState {
 // as one object so they persist across tab navigation within a live session;
 // the screen unmounts on tab switch, so local state would be lost (#1414/#1417).
 export interface ToolsUiState {
-  selectedToolName?: string;
+  /**
+   * The selected row's `toolRowKey` — its position in the list plus its name,
+   * not the name alone. A `tools/list` may repeat a name, and identifying the
+   * selection by name highlighted every copy while the detail panel always
+   * resolved the first, so the later copies could not be inspected (#2001).
+   * The protocol name a `tools/call` sends still comes from the resolved tool.
+   */
+  selectedToolKey?: string;
   formValues: Record<string, unknown>;
   search: string;
   // Screen-level "Run as task" toggle, shared across tools (not per-tool):
@@ -168,27 +176,25 @@ export function ToolsScreen({
   onClearResult,
   onReadResource,
 }: ToolsScreenProps) {
-  const { selectedToolName, formValues, search } = ui;
+  const { selectedToolKey, formValues, search } = ui;
-  const selectedTool = selectedToolName
+  const selectedTool = findToolByRowKey(tools, selectedToolKey);
-    ? tools.find((t) => t.name === selectedToolName)
-    : undefined;
   const isExecuting = callState?.status === "pending";
 
-  const handleSelectTool = (name: string) => {
+  const handleSelectTool = (key: string) => {
     // Seed the form with the tool's schema defaults so default-only fields the
     // user never edits are still sent on execute (the form shows defaults via
     // resolveValue, but onChange only writes edited fields).
-    const tool = tools.find((t) => t.name === name);
+    const tool = findToolByRowKey(tools, key);
-    // `name` always comes from the rendered tools list (ToolControls only emits
+    // `key` always comes from the rendered tools list (ToolControls only emits
-    // names it was given), so the lookup never misses; the empty-object fallback
+    // keys it computed from the tools it was given), so the lookup never misses;
-    // is an unreachable defensive default.
+    // the empty-object fallback is an unreachable defensive default.
     let nextFormValues: Record<string, unknown> = {};
-    /* v8 ignore next -- unreachable: onSelectTool always names a tool in the list */
+    /* v8 ignore next -- unreachable: onSelectTool always keys a tool in the list */
     if (tool)
       nextFormValues = collectSchemaDefaults(
         toFormSchema(tool.inputSchema) ?? {},
       );
-    onUiChange({ ...ui, selectedToolName: name, formValues: nextFormValues });
+    onUiChange({ ...ui, selectedToolKey: key, formValues: nextFormValues });
   };
 
   return (
@@ -199,7 +205,7 @@ export function ToolsScreen({
             tools={tools}
             excludedTools={excludedTools}
             malformedListItems={malformedListItems}
-            selectedName={selectedToolName}
+            selectedKey={selectedToolKey}
             searchText={search}
             listChanged={listChanged}
             onRefreshList={onRefreshList}

clients/web/src/components/screens/screenUiState.ts

@@ -16,7 +16,7 @@ import { ALL_LEVELS_VISIBLE } from "./LoggingScreen/logLevels";
 import { ALL_CATEGORIES_VISIBLE } from "./NetworkScreen/fetchCategories";
 
 export const EMPTY_TOOLS_UI: ToolsUiState = {
-  selectedToolName: undefined,
+  selectedToolKey: undefined,
   formValues: {},
   search: "",
   runAsTask: false,

clients/web/src/lib/oauthResume.test.ts

@@ -80,7 +80,7 @@ describe("oauthResume", () => {
       tabUi: {
         Tools: {
           ...EMPTY_TOOLS_UI,
-          selectedToolName: "echo",
+          selectedToolKey: "0:echo",
           formValues: { message: "hi" },
         },
       },
@@ -96,7 +96,7 @@ describe("oauthResume", () => {
   it("builds and restores tab ui snapshots", () => {
     const toolsUi = {
       ...EMPTY_TOOLS_UI,
-      selectedToolName: "get_temp",
+      selectedToolKey: "1:get_temp",
       formValues: { city: "NYC" },
     };
     const tabUi = buildTabUiSnapshot({
@@ -123,6 +123,40 @@ describe("oauthResume", () => {
     expect(setToolsUi).toHaveBeenCalledWith(toolsUi);
   });
 
+  it("drops a pre-#2001 selectedToolName from a legacy snapshot, keeping the rest", () => {
+    // A redirect begun on a build that keyed tool selection by name, restored
+    // on one that keys it by row identity (the app upgraded mid-redirect).
+    // The name can't be mapped to a row key here — the tools list is fetched
+    // after reconnect — so the selection is dropped, not carried through as a
+    // stray field, and everything else survives.
+    const setToolsUi = vi.fn();
+    restoreTabUiFromSnapshot(
+      {
+        Tools: {
+          formValues: { city: "NYC" },
+          search: "get",
+          runAsTask: false,
+          selectedToolName: "get_temp",
+        },
+      },
+      {
+        setToolsUi,
+        setPromptsUi: vi.fn(),
+        setResourcesUi: vi.fn(),
+        setAppsUi: vi.fn(),
+        setTasksUi: vi.fn(),
+        setLogsUi: vi.fn(),
+        setProtocolUi: vi.fn(),
+        setNetworkUi: vi.fn(),
+      },
+    );
+    expect(setToolsUi).toHaveBeenCalledWith({
+      formValues: { city: "NYC" },
+      search: "get",
+      runAsTask: false,
+    });
+  });
+
   it("falls back to legacy pending server key", () => {
     storage.set(OAUTH_PENDING_SERVER_KEY, "legacy-srv");
     const snapshot = readOAuthResumeSnapshot();
@@ -186,7 +220,7 @@ describe("oauthResume", () => {
   it("applyOAuthResumeUi restores tab ui, active tab, and clears in-flight panels", () => {
     const toolsUi = {
       ...EMPTY_TOOLS_UI,
-      selectedToolName: "get_temp",
+      selectedToolKey: "1:get_temp",
       formValues: { city: "NYC" },
     };
     const snapshot: OAuthResumeSnapshot = {

clients/web/src/lib/oauthResume.ts

@@ -96,6 +96,23 @@ export function buildTabUiSnapshot(
   };
 }
 
+/**
+ * A snapshot written before #2001 carries `selectedToolName` (a tool's name)
+ * where {@link ToolsUiState} now expects `selectedToolKey` (its `index:name`
+ * row identity). A snapshot only lives for the length of one OAuth redirect,
+ * so this matters exactly when the app is upgraded mid-redirect — and the name
+ * cannot be mapped to a row key here, since the tools list is fetched after
+ * reconnect, long after restore. So the stale selection is dropped rather than
+ * carried as a stray field that would be re-serialized on the next redirect;
+ * the rest of the tab state (search text, form values) is restored intact and
+ * the screen opens on its "select a tool" placeholder.
+ */
+function normalizeToolsUi(value: unknown): ToolsUiState {
+  const ui = { ...((value as ToolsUiState | undefined) ?? EMPTY_TOOLS_UI) };
+  delete (ui as ToolsUiState & { selectedToolName?: string }).selectedToolName;
+  return ui;
+}
+
 export function restoreTabUiFromSnapshot(
   tabUi: Partial<Record<InspectorTabId, unknown>> | undefined,
   setters: TabUiSetters,
@@ -110,9 +127,7 @@ export function restoreTabUiFromSnapshot(
     const value = tabUi[tabId];
     switch (tabId) {
       case "Tools":
-        setters.setToolsUi(
+        setters.setToolsUi(normalizeToolsUi(value));
-          (value as ToolsUiState | undefined) ?? EMPTY_TOOLS_UI,
-        );
         break;
       case "Prompts":
         setters.setPromptsUi(

clients/web/src/utils/toolUtils.test.ts

@@ -1,6 +1,11 @@
 import { describe, it, expect } from "vitest";
 import type { Tool } from "@modelcontextprotocol/client";
-import { hasInputFields, resolveDisplayLabel } from "./toolUtils";
+import {
+  findToolByRowKey,
+  hasInputFields,
+  resolveDisplayLabel,
+  toolRowKey,
+} from "./toolUtils";
 
 describe("resolveDisplayLabel", () => {
   it("returns the title when provided", () => {
@@ -47,3 +52,37 @@ describe("hasInputFields", () => {
     ).toBe(true);
   });
 });
+
+describe("toolRowKey / findToolByRowKey", () => {
+  const tool = (name: string): Tool => ({
+    name,
+    inputSchema: { type: "object" },
+  });
+  // A `tools/list` may legitimately repeat a name (#1957/#2001).
+  const tools: Tool[] = [
+    tool("get_weather"),
+    tool("echo"),
+    tool("get_weather"),
+  ];
+
+  it("distinguishes two tools that share a name", () => {
+    expect(toolRowKey("get_weather", 0)).not.toBe(toolRowKey("get_weather", 2));
+  });
+
+  it("resolves each duplicate to its own entry", () => {
+    expect(findToolByRowKey(tools, "0:get_weather")).toBe(tools[0]);
+    // The second copy — the one a name-based lookup could never reach.
+    expect(findToolByRowKey(tools, "2:get_weather")).toBe(tools[2]);
+  });
+
+  it("returns undefined for no key", () => {
+    expect(findToolByRowKey(tools, undefined)).toBeUndefined();
+  });
+
+  it("returns undefined for a key naming no current row", () => {
+    // A stale selection after the list changed underneath it.
+    expect(findToolByRowKey(tools, "9:gone")).toBeUndefined();
+    // Right name, wrong position: still not a match.
+    expect(findToolByRowKey(tools, "1:get_weather")).toBeUndefined();
+  });
+});

clients/web/src/utils/toolUtils.ts

@@ -19,3 +19,35 @@ export function resolveDisplayLabel(name: string, title?: string): string {
 export function hasInputFields(tool: Tool): boolean {
   return Object.keys(tool.inputSchema.properties ?? {}).length > 0;
 }
+
+/**
+ * A tool's stable per-row identity in the Tools sidebar.
+ *
+ * A server may return the same tool name more than once, so the name alone
+ * identifies neither a React child nor a selection: colliding keys let a
+ * filtered-out row survive reconciliation (#1957), and a name-keyed selection
+ * highlights both copies at once while the detail panel can only ever resolve
+ * the first (#2001). The tool's position in the *unfiltered* list disambiguates
+ * duplicates and stays stable while the search narrows, since it is captured
+ * before filtering.
+ *
+ * This is a UI identity only — the wire identity is still `tool.name`, which is
+ * what a `tools/call` must send.
+ */
+export function toolRowKey(name: string, sourceIndex: number): string {
+  return `${sourceIndex}:${name}`;
+}
+
+/**
+ * Resolves the tool a {@link toolRowKey} refers to, or `undefined` when the key
+ * names no row in the current list (e.g. the list changed under a stale
+ * selection). Compares computed keys rather than parsing the key, so the two
+ * stay in lockstep if the format ever changes.
+ */
+export function findToolByRowKey(
+  tools: Tool[],
+  key: string | undefined,
+): Tool | undefined {
+  if (key === undefined) return undefined;
+  return tools.find((tool, index) => toolRowKey(tool.name, index) === key);
+}

specification/v2_storage.md

@@ -304,7 +304,9 @@ interface LogsDisplayActions {
 ```typescript
 interface ExecutionFormState {
   // Tools
-  selectedToolName: string | null;
+  // The selected row's `toolRowKey` (`index:name`), not the tool's name — a
+  // `tools/list` may repeat a name (#2001).
+  selectedToolKey: string | null;
   toolFormValues: Record<string, unknown>;
   lastToolResult: ToolResult | null;
 

specification/v2_ux_interfaces.md

@@ -646,7 +646,8 @@ will close out as part of that work.
 - **Purpose**: Searchable tool list sidebar with list-changed indicator.
 - **Current props**: `tools: ToolListItemProps[]`, `listChanged`, `onRefreshList`, `onSelectTool`.
 - **MCP schema touch points**: `Tool`, `ListToolsResult`, `ToolListChangedNotification`.
-- **Target props**: `tools: Tool[]`, `selectedName?`, `listChanged`, `onRefreshList`, `onSelectTool`.
+- **Target props**: `tools: Tool[]`, `selectedKey?`, `listChanged`, `onRefreshList`, `onSelectTool`.
+- **Row identity**: a `tools/list` may repeat a name, so rows are keyed — for React reconciliation *and* for selection — by `toolRowKey(name, sourceIndex)` (`utils/toolUtils.ts`), not by `tool.name`. `selectedKey` and `onSelectTool` both carry that key (#1957/#2001).
 - **Callbacks → core hook**: `useManagedTools`.
 - **Internal refactors**: Consume schema `Tool[]` directly.
 
@@ -716,14 +717,14 @@ themselves — every callback passed down must originate in a core hook.
 - **MCP schema touch points**: `Tool`, `ListToolsResult`, `CallToolRequest.params`, `CallToolResult`, `ToolListChangedNotification`.
 - **Target props**:
   - `tools: Tool[]` — raw MCP `Tool[]` from `ListToolsResult.tools`.
-  - `selectedToolName?: string` — selection is screen-local; detail derived from `tools`.
+  - `selectedToolKey?: string` — selection is screen-local; detail derived from `tools`. This is the row's `toolRowKey`, not its name: duplicate names would otherwise select every copy at once and resolve only the first (#2001).
   - `callState?: { status: 'idle' | 'pending' | 'ok' | 'error'; request?: CallToolRequest['params']; result?: CallToolResult; error?: string }`.
   - `listChanged: boolean` — driven by `notifications/tools/list_changed`.
-  - `onRefreshList: () => void`, `onSelectTool: (name: string) => void`, `onCallTool: (name: string, args: Record<string, unknown>) => void`.
+  - `onRefreshList: () => void`, `onSelectTool: (key: string) => void`, `onCallTool: (name: string, args: Record<string, unknown>) => void` — note `onSelectTool` carries the row key (UI identity) while `onCallTool` carries the protocol name (wire identity).
 - **Callbacks → core hook**: `useManagedTools` provides `tools`, `listChanged`, `refreshTools`, `callTool`, `lastCallResult`; backed by `useInspectorClient` for the underlying `client.request`.
 - **Internal refactors**:
   - Stop flattening `Tool` into `ToolListItemProps` at the screen boundary — pass `Tool` down and let `ToolListItem` project fields.
-  - Derive the selected tool from `tools.find(t => t.name === selectedToolName)` instead of receiving a pre-built `ToolDetailPanelProps`.
+  - Derive the selected tool from `findToolByRowKey(tools, selectedToolKey)` instead of receiving a pre-built `ToolDetailPanelProps`.
   - Replace the separate `result` prop with a unified `callState` so pending/error UI can be rendered by `ToolResultPanel`.
 
 ### PromptsScreen