Tools: x-mcp-header annotation tooling + -32602 unknown-tool rendering (#1632) (#1735)

* Tools: x-mcp-header annotation tooling + -32602 unknown-tool rendering (#1632)

Card 9/10 of the SDK-v2 + New Spec stack. Adds SEP-2243 `x-mcp-header`
tooling to the Tools tab and adjusts result rendering for SDK v2's
unknown-tool behavior, and bumps the SDK to 2.0.0-beta.5.

- **`core/json/xMcpHeader.ts`**: a faithful port of the SDK's (non-public)
  `scanXMcpHeaderDeclarations` — validates every SEP-2243 constraint
  (primitive types incl. `number`, RFC 9110 token, case-insensitive
  uniqueness, statically-reachable `properties`-only chain) and derives the
  mirrored `Mcp-Param-{Name}` params for a kept tool.

- **Excluded tools**: the SDK silently drops tools with invalid annotations
  from `tools/list`. InspectorClient now re-lists the RAW (unfiltered) list
  and scans it to recompute the excluded set with reasons — gated to the
  modern non-stdio era (matching the SDK's gate), recomputed on every
  aggregate refresh, surfaced via a new `excludedToolsChange` event +
  `getExcludedTools()` and `useInspectorClient().excludedTools`. The Tools
  sidebar lists them struck-through under an "Excluded (SEP-2243)" divider
  with the reason on hover.

- **Mirrored args**: ToolDetailPanel shows a "Mirrored request headers"
  section listing each arg → `Mcp-Param-{Name}` (with the browser-omits note).

- **-32602 rendering**: SDK v2 rejects an unknown-tool call with `-32602`
  instead of an `isError` result, which previously rendered nothing. New
  ToolCallErrorPanel renders a thrown tool-call error, with a targeted
  "Unknown Tool" hint for `-32602`.

Adds unit + Storybook + integration coverage (a real modern server with an
invalid-header tool fixture) for every path. `npm run ci`-equivalent checks
green.

Closes #1632

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* test-servers: x-mcp-header modern showcase config + preset (#1632)

Register the `invalid_header_tool` fixture as a preset and add
`xmcpheader-modern-http.json` — a modern HTTP showcase serving echo, a
valid-header `get_weather`, and the invalid-header tool — so the Tools-tab
x-mcp-header tooling (mirrored headers, excluded-tools surface, -32602
rendering) can be exercised manually. Documented in the README alongside the
other per-SEP showcase configs. Smoke-tested end to end in the web client.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* docs: add #1632 proof screenshots to pr-screenshots

End-to-end web-client verification of the x-mcp-header Tools tooling against
the modern showcase server: excluded-tools surface + reason, mirrored-headers
section, and the -32602 unknown-tool error panel.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* Respond to review: disambiguate -32602, doc/search nits (#1632)

Addresses the review on PR #1735:

1. -32602 "Unknown Tool" mislabel: `-32602` is generic Invalid params, so a
   known tool called with bad arguments hit the same code and rendered under
   the definitive "Unknown Tool" heading. Replace `isUnknownToolError` with
   `classifyToolCallError(code, message)` → "unknown-tool" only when the
   message names it (not found / unknown tool / …), else "invalid-params"
   (new "Invalid Parameters" heading + schema hint), else "generic".

2. Double pagination walk: expand the `listAllTools` comment to document that
   the excluded-tools recompute is a deliberately un-cached second raw walk
   (doubles list round-trips on modern non-stdio, runs even on a cache-served
   aggregate) — accepted for a debugging tool, no-op on legacy/stdio.

3. Doc nit: `scanXMcpHeaderDeclarations` no longer claims to visit "$ref
   targets" — reworded to note `$ref` is never followed (refs resolve into the
   unreachable `$defs` body).

4. Search nit: the excluded-list filter now matches name AND title, matching
   the main tools filter.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* Tighten unknown-tool matcher to be tool-scoped (#1632 re-review nit)

The re-review noted the -32602 disambiguation was symmetric: broad markers
("does not exist", "unrecognized") could inversely mislabel a genuine
invalid-params message (e.g. "property 'region' does not exist") as "Unknown
Tool". Scope the not-found/does-not-exist family to require the word "tool" in
the same clause (matching the SDK's "Tool <name> not found"); keep "unknown
tool" / "no such tool" as standalone unambiguous markers. Adds a
tool-less-"does not exist" test asserting it classifies as invalid-params.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

* Add trigger_invalid_params showcase tool + Invalid Parameters screenshot (#1632)

Adds a `trigger_invalid_params` spec-error trigger to the modern showcase
server: the injector answers its `tools/call` with a real `-32602 Invalid
params` JSON-RPC error whose message does NOT name an unknown tool. This lets
the "Invalid Parameters" branch of the tool-call error panel (added in the
review response) be exercised live, distinct from the unknown-tool `-32602`.

- `SPEC_ERROR_TRIGGERS` gains the `trigger_invalid_params` entry (HTTP 200,
  in-band -32602) + preset registration.
- Enable `injectSpecErrors` on `xmcpheader-modern-http.json` and add the tool.
- README + pr-screenshots README document it; adds the live "Invalid
  Parameters" proof screenshot.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNdjEPKLG637X8YmhDiEk5

---------

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Cliff Hall 2026-07-22 11:42:54 -04:00 • committed by GitHub
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11 changed files with 1610 additions and 86 deletions

View file

@ -135,4 +135,52 @@ describe("ToolControls", () => {
expect(screen.getByText("Tools")).toBeInTheDocument();
expect(screen.queryByText("git_status")).not.toBeInTheDocument();
});
const excludedFixture = [
{
tool: {
name: "invalid_header_tool",
inputSchema: { type: "object" as const },
},
reason:
"value: x-mcp-header 'Bad Header' is not a valid RFC 9110 token (no spaces, control characters or HTTP delimiters)",
},
];
it("renders excluded tools with a header and the tool name (#1632)", () => {
renderWithMantine(
<ToolControls {...baseProps} excludedTools={excludedFixture} />,
);
expect(screen.getByText("Excluded (SEP-2243)")).toBeInTheDocument();
expect(screen.getByText("invalid_header_tool")).toBeInTheDocument();
});
it("does not render the excluded section when there are none", () => {
renderWithMantine(<ToolControls {...baseProps} excludedTools={[]} />);
expect(screen.queryByText("Excluded (SEP-2243)")).not.toBeInTheDocument();
});
it("filters excluded tools by the search text (#1632)", () => {
renderWithMantine(
<ToolControls
{...baseProps}
excludedTools={excludedFixture}
searchText="git"
/>,
);
// The search matches no excluded tool, so the section is hidden.
expect(screen.queryByText("Excluded (SEP-2243)")).not.toBeInTheDocument();
expect(screen.queryByText("invalid_header_tool")).not.toBeInTheDocument();
});
it("keeps a matching excluded tool visible under search (#1632)", () => {
renderWithMantine(
<ToolControls
{...baseProps}
excludedTools={excludedFixture}
searchText="invalid"
/>,
);
expect(screen.getByText("invalid_header_tool")).toBeInTheDocument();
});
});

View file

@ -1,6 +1,18 @@
import { Group, ScrollArea, Stack, TextInput, Title } from "@mantine/core";
import {
Divider,
Group,
ScrollArea,
Stack,
Text,
TextInput,
ThemeIcon,
Title,
Tooltip,
} from "@mantine/core";
import { RiErrorWarningLine } from "react-icons/ri";
import { ClearButton } from "../../elements/ClearButton/ClearButton";
import type { Tool } from "@modelcontextprotocol/client";
import type { ExcludedTool } from "@inspector/core/mcp/types.js";
import { ListChangedIndicator } from "../../elements/ListChangedIndicator/ListChangedIndicator";
import {
ListPaginationControls,
@ -11,6 +23,9 @@ import { useScrollMemory } from "../../../hooks/useScrollMemory";
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;
// Search text is controlled by the parent (App, via ToolsScreen) so it
// persists across tab navigation within a live session — see #1417.
@ -23,8 +38,31 @@ export interface ToolControlsProps {
onSelectTool: (name: string) => void;
}
// One excluded tool: a warning icon, the tool name (struck through, since it is
// not callable), and its reason on hover. `wrap: nowrap` keeps the icon pinned.
const ExcludedRow = Group.withProps({
gap: "xs",
wrap: "nowrap",
align: "center",
});
const ExcludedWarningIcon = ThemeIcon.withProps({
size: "sm",
variant: "transparent",
c: "var(--inspector-log-warning)",
"aria-hidden": true,
});
const ExcludedName = Text.withProps({
size: "sm",
td: "line-through",
c: "var(--inspector-text-secondary)",
truncate: "end",
});
export function ToolControls({
tools,
excludedTools = [],
selectedName,
searchText = "",
listChanged,
@ -42,6 +80,15 @@ export function ToolControls({
(tool.title?.toLowerCase().includes(query) ?? false),
)
: tools;
// Excluded tools are searchable too, matching name AND title like the main
// list above, so a filtered view stays consistent.
const filteredExcluded = searchText
? excludedTools.filter(
({ tool }) =>
tool.name.toLowerCase().includes(query) ||
(tool.title?.toLowerCase().includes(query) ?? false),
)
: excludedTools;
return (
// Fill the full-height `sidebar` Card (a flex column) so the scroll region
@ -81,6 +128,32 @@ export function ToolControls({
}}
/>
))}
{filteredExcluded.length > 0 && (
<>
<Divider
label="Excluded (SEP-2243)"
labelPosition="left"
mt="sm"
/>
{filteredExcluded.map(({ tool, reason }) => (
<Tooltip
key={tool.name}
label={reason}
multiline
w={280}
withArrow
position="right"
>
<ExcludedRow>
<ExcludedWarningIcon>
<RiErrorWarningLine />
</ExcludedWarningIcon>
<ExcludedName>{tool.name}</ExcludedName>
</ExcludedRow>
</Tooltip>
))}
</>
)}
</Stack>
</ScrollArea>
</Stack>

View file

@ -469,4 +469,37 @@ describe("ToolDetailPanel", () => {
expect(onExecute).toHaveBeenCalledWith(false);
});
});
describe("mirrored request headers (SEP-2243, #1632)", () => {
const mirroredTool: Tool = {
name: "get_weather",
inputSchema: {
type: "object",
properties: {
city: { type: "string", "x-mcp-header": "City" },
country: { type: "string", "x-mcp-header": "Country" },
},
},
};
it("lists each mirrored arg and its Mcp-Param header", () => {
renderWithMantine(<ToolDetailPanel {...baseProps} tool={mirroredTool} />);
expect(
screen.getByText("Mirrored request headers (SEP-2243)"),
).toBeInTheDocument();
// The header names are unique to this section (the arg names `city` /
// `country` also appear as form-field labels below).
expect(screen.getByText("Mcp-Param-City")).toBeInTheDocument();
expect(screen.getByText("Mcp-Param-Country")).toBeInTheDocument();
// The arg path renders in a <code> alongside its header.
expect(screen.getAllByText("city").length).toBeGreaterThanOrEqual(1);
});
it("omits the section for a tool without x-mcp-header annotations", () => {
renderWithMantine(<ToolDetailPanel {...baseProps} tool={simpleTool} />);
expect(
screen.queryByText("Mirrored request headers (SEP-2243)"),
).not.toBeInTheDocument();
});
});
});

View file

@ -1,6 +1,7 @@
import {
ActionIcon,
Button,
Code,
Collapse,
Divider,
Group,
@ -19,6 +20,7 @@ import type {
} from "@modelcontextprotocol/client";
import { resolveDisplayLabel } from "../../../utils/toolUtils";
import { toFormSchema } from "../../../utils/jsonUtils";
import { getMirroredHeaderParams } from "@inspector/core/json/xMcpHeader.js";
import { AnnotationBadge } from "../../elements/AnnotationBadge/AnnotationBadge";
import { ProgressDisplay } from "../../elements/ProgressDisplay/ProgressDisplay";
import { SchemaForm } from "../SchemaForm/SchemaForm";
@ -139,6 +141,34 @@ const RunAsTaskSwitch = Switch.withProps({
label: "Run as task",
});
// Header-mirroring section (SEP-2243): lists which args mirror their value into
// an `Mcp-Param-{Name}` header on `tools/call`. `Stack` (not `Box`) so the
// constant can carry props; the heading + note pin above the mapping rows.
const HeaderParamsSection = Stack.withProps({
gap: "xs",
});
const HeaderParamsTitle = Text.withProps({
size: "sm",
fw: 600,
});
const HeaderParamsNote = Text.withProps({
size: "xs",
c: "var(--inspector-text-secondary)",
});
// One `arg → Mcp-Param-{Name}` mapping row.
const HeaderParamRow = Group.withProps({
gap: "xs",
wrap: "nowrap",
});
const HeaderParamArrow = Text.withProps({
size: "sm",
c: "var(--inspector-text-secondary)",
});
// A tool's per-tool task support, defaulting to "forbidden" (the SDK default
// when `execution` is absent) so tools that say nothing can't be run as tasks.
type TaskSupport = "forbidden" | "optional" | "required";
@ -173,6 +203,9 @@ export function ToolDetailPanel({
// Narrow the SDK protocol schema to the form renderer's schema type.
const formSchema = toFormSchema(inputSchema) ?? {};
const iconSrc = icons?.[0]?.src;
// SEP-2243: args this tool declares as `x-mcp-header` — their values mirror
// into `Mcp-Param-{Name}` headers on a `tools/call` (#1632).
const mirroredParams = getMirroredHeaderParams(tool);
// Descriptions are shown by default (most are short); the chevron lets the
// user hide a long one to keep the form and Execute footer in view. Reset to
@ -259,6 +292,26 @@ export function ToolDetailPanel({
<Divider />
{mirroredParams.length > 0 && (
<HeaderParamsSection>
<HeaderParamsTitle>
Mirrored request headers (SEP-2243)
</HeaderParamsTitle>
{mirroredParams.map((param) => (
<HeaderParamRow key={param.path}>
<Code>{param.path}</Code>
<HeaderParamArrow>→</HeaderParamArrow>
<Code>{param.header}</Code>
</HeaderParamRow>
))}
<HeaderParamsNote>
These argument values are mirrored into HTTP headers on the
call. The SDK sends them only on a Node/proxy transport — the
browser omits <Code>Mcp-Param-*</Code> headers.
</HeaderParamsNote>
</HeaderParamsSection>
)}
<SchemaForm
schema={formSchema}
values={formValues}

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@ -0,0 +1,44 @@
import type { Decorator, Meta, StoryObj } from "@storybook/react-vite";
import { Card, Flex } from "@mantine/core";
import { fn } from "storybook/test";
import { ToolCallErrorPanel } from "./ToolCallErrorPanel";
// Frame the panel in the same result card the Tools screen uses, so the story
// shows it at its real width/height.
const inCardDecorators: Decorator[] = [
(Story) => (
<Flex h={360} direction="column" align="stretch">
<Card withBorder padding="lg" variant="preview">
<Story />
</Card>
</Flex>
),
];
const meta: Meta<typeof ToolCallErrorPanel> = {
title: "Groups/ToolCallErrorPanel",
component: ToolCallErrorPanel,
args: {
onClear: fn(),
},
decorators: inCardDecorators,
};
export default meta;
type Story = StoryObj<typeof ToolCallErrorPanel>;
// A generic thrown protocol/SDK error (no special code).
export const GenericError: Story = {
args: {
error: "MCP error -32603: Internal error while executing the tool",
},
};
// SDK v2's unknown-tool rejection: `-32602` arrives as a thrown error, not an
// `isError` result, so it renders here with the targeted "Unknown Tool" hint.
export const UnknownTool: Story = {
args: {
error: "MCP error -32602: Invalid params: unknown tool 'ghost_tool'",
errorCode: -32602,
},
};

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@ -0,0 +1,78 @@
import { describe, it, expect, vi } from "vitest";
import userEvent from "@testing-library/user-event";
import { renderWithMantine, screen } from "../../../test/renderWithMantine";
import { ToolCallErrorPanel } from "./ToolCallErrorPanel";
import { classifyToolCallError } from "./toolResultUtils";
describe("ToolCallErrorPanel", () => {
it("renders a generic thrown error with the plain title and message", () => {
renderWithMantine(
<ToolCallErrorPanel error="Internal error" onClear={vi.fn()} />,
);
expect(screen.getByText("Tool Call Failed")).toBeInTheDocument();
expect(screen.getByText("Tool Error")).toBeInTheDocument();
expect(screen.getByText("Internal error")).toBeInTheDocument();
// No -32602 hints for a generic error.
expect(screen.queryByText(/does not recognize this tool/)).toBeNull();
expect(screen.queryByText(/against the tool/)).toBeNull();
});
it("renders the unknown-tool heading + hint when the message names it (#1632)", () => {
renderWithMantine(
<ToolCallErrorPanel
error="MCP error -32602: Tool echo not found"
errorCode={-32602}
onClear={vi.fn()}
/>,
);
expect(screen.getByText("Unknown Tool")).toBeInTheDocument();
expect(
screen.getByText(/does not recognize this tool/),
).toBeInTheDocument();
});
it("renders Invalid Parameters for a -32602 that is NOT an unknown tool (#1632)", () => {
// Same code, but the message is about bad arguments for a known tool — must
// not be mislabelled "Unknown Tool".
renderWithMantine(
<ToolCallErrorPanel
error="MCP error -32602: Invalid params: 'count' must be a number"
errorCode={-32602}
onClear={vi.fn()}
/>,
);
expect(screen.getByText("Invalid Parameters")).toBeInTheDocument();
expect(screen.getByText(/against the tool/)).toBeInTheDocument();
expect(screen.queryByText(/does not recognize this tool/)).toBeNull();
});
it("invokes onClear when the close button is clicked", async () => {
const user = userEvent.setup();
const onClear = vi.fn();
renderWithMantine(<ToolCallErrorPanel error="boom" onClear={onClear} />);
await user.click(screen.getByRole("button", { name: "Close error" }));
expect(onClear).toHaveBeenCalledTimes(1);
});
it("classifyToolCallError narrows -32602 by message", () => {
expect(classifyToolCallError(-32602, "Tool foo not found")).toBe(
"unknown-tool",
);
expect(classifyToolCallError(-32602, "unknown tool: foo")).toBe(
"unknown-tool",
);
// -32602 without an unknown-tool marker → invalid params, not unknown tool.
expect(classifyToolCallError(-32602, "bad argument type")).toBe(
"invalid-params",
);
expect(classifyToolCallError(-32602)).toBe("invalid-params");
// A tool-less "does not exist" (arg-validation message) must NOT read as an
// unknown tool — the match is tool-scoped.
expect(
classifyToolCallError(-32602, "property 'region' does not exist in enum"),
).toBe("invalid-params");
// Any other code (or none) is generic.
expect(classifyToolCallError(-32601, "Tool not found")).toBe("generic");
expect(classifyToolCallError(undefined)).toBe("generic");
});
});

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@ -0,0 +1,99 @@
import {
Alert,
CloseButton,
Code,
Group,
Stack,
Text,
Title,
} from "@mantine/core";
import { classifyToolCallError } from "./toolResultUtils";
export interface ToolCallErrorPanelProps {
/** The thrown error's message (already stringified in App). */
error: string;
/**
* The JSON-RPC error code, when the throw was a `ProtocolError`. Under SDK v2
* an unknown-tool `tools/call` REJECTS with `-32602 Invalid params` instead of
* resolving an `isError` result, so it arrives here as a thrown error rather
* than a `CallToolResult` (which the ToolResultPanel would render). The same
* `-32602` is also thrown for a known tool called with invalid arguments, so
* the heading/hint are chosen from the message, not the code alone.
*/
errorCode?: number;
/** Dismiss the error and return to the input form (mirrors ToolResultPanel). */
onClear: () => void;
}
// Mirrors ToolResultPanel's column so an error dismisses the same way a result
// does: header with the close X pins, the alert fills and scrolls below it.
const PanelStack = Stack.withProps({
gap: "md",
miw: 0,
mih: 0,
flex: 1,
});
const HeaderRow = Group.withProps({
gap: "xs",
wrap: "nowrap",
flex: "0 0 auto",
});
const HintText = Text.withProps({
size: "sm",
c: "var(--inspector-text-secondary)",
});
/**
* Renders a thrown tool-call error (a protocol/SDK-level rejection) as a
* distinct error panel. This is separate from ToolResultPanel, which renders a
* `CallToolResult` (including a tool-level `isError` result). An `-32602`
* rejection carries no result, so it would otherwise be invisible.
*/
const ERROR_TITLES: Record<string, string> = {
"unknown-tool": "Unknown Tool",
"invalid-params": "Invalid Parameters",
generic: "Tool Error",
};
export function ToolCallErrorPanel({
error,
errorCode,
onClear,
}: ToolCallErrorPanelProps) {
const kind = classifyToolCallError(errorCode, error);
return (
<PanelStack>
<HeaderRow>
<CloseButton aria-label="Close error" onClick={onClear} />
{/* h3 (not h4), size h4: request modals open over the Tools screen with
an `h2` `Modal.Title`, so an `h4` here would skip a level (axe
`heading-order`); `size="h4"` keeps the visual size. */}
<Title order={3} size="h4">
Tool Call Failed
</Title>
</HeaderRow>
<Alert color="red" variant="light" title={ERROR_TITLES[kind]}>
<Stack gap="xs">
<Text size="sm">{error}</Text>
{kind === "unknown-tool" && (
<HintText>
The server rejected this call with <Code>-32602</Code> (Invalid
params) — it does not recognize this tool. It may have been
excluded for an invalid <Code>x-mcp-header</Code> annotation or
removed since the list was last fetched. Try refreshing the tools
list.
</HintText>
)}
{kind === "invalid-params" && (
<HintText>
The server rejected this call with <Code>-32602</Code> (Invalid
params). Check the argument values against the tool&apos;s schema.
</HintText>
)}
</Stack>
</Alert>
</PanelStack>
);
}

View file

@ -1,4 +1,45 @@
import type { CallToolResult } from "@modelcontextprotocol/client";
import { ProtocolErrorCode } from "@modelcontextprotocol/client";
/** How a thrown `tools/call` error should be presented in the error panel. */
export type ToolCallErrorKind = "unknown-tool" | "invalid-params" | "generic";
/**
* Whether a `-32602` message names the *tool itself* as unrecognized, as
* opposed to reporting bad arguments for a known tool. Both reject with the same
* `-32602 Invalid params` code under SDK v2, so the code alone can't tell them
* apart — matching the message lets us pick the right heading instead of
* labelling every `-32602` "Unknown Tool" (which would mislabel a known tool
* called with invalid arguments).
*
* The match is deliberately tool-scoped so it doesn't INVERSELY mislabel: an
* argument-validation message like `"property 'region' does not exist"` must
* NOT read as "Unknown Tool". So the "not found / does not exist / unknown /
* unrecognized" family only counts when the word "tool" is in the same clause
* (the SDK's own message is `Tool <name> not found`); `unknown tool` / `no such
* tool` are unambiguous on their own. Case-insensitive; best-effort — the fully
* unambiguous signal would be a tool name in `error.data`, which the SDK does
* not currently surface here.
*/
const UNKNOWN_TOOL_MESSAGE =
/\b(unknown tool|no such tool)\b|\btool\b[^.!?]*\b(not found|not recognized|does not exist|is unknown|unrecognized)\b/i;
/**
* Classify a thrown tool-call error for display (#1632). Under SDK v2 an
* unknown-tool `tools/call` REJECTS with `-32602 Invalid params` instead of
* resolving an `isError` result — but so does a *known* tool called with
* invalid arguments (server-side schema validation). We narrow the ambiguous
* `-32602` to `"unknown-tool"` only when the message says so; any other
* `-32602` is `"invalid-params"`, and every other code is `"generic"`.
*/
export function classifyToolCallError(
errorCode?: number,
message?: string,
): ToolCallErrorKind {
if (errorCode !== ProtocolErrorCode.InvalidParams) return "generic";
if (message && UNKNOWN_TOOL_MESSAGE.test(message)) return "unknown-tool";
return "invalid-params";
}
/**
* Whether a result renders a "Resource Links" box — i.e. a non-error result

View file

@ -319,4 +319,54 @@ describe("ToolsScreen", () => {
await user.click(screen.getByRole("button", { name: "Close results" }));
expect(screen.getByText("Results")).toBeInTheDocument();
});
it("renders a thrown error (no result) as an error panel (#1632)", () => {
renderWithMantine(
<ToolsScreen
{...baseProps}
callState={{ status: "error", error: "boom", errorCode: -32603 }}
/>,
);
expect(screen.getByText("Tool Call Failed")).toBeInTheDocument();
expect(screen.getByText("boom")).toBeInTheDocument();
});
it("renders the unknown-tool hint for a -32602 rejection (#1632)", async () => {
const user = userEvent.setup();
const onClearResult = vi.fn();
renderWithMantine(
<ToolsScreen
{...baseProps}
onClearResult={onClearResult}
callState={{
status: "error",
error: "MCP error -32602: Tool ghost_tool not found",
errorCode: -32602,
}}
/>,
);
expect(screen.getByText("Unknown Tool")).toBeInTheDocument();
await user.click(screen.getByRole("button", { name: "Close error" }));
expect(onClearResult).toHaveBeenCalledTimes(1);
});
it("renders excluded tools in the sidebar with the reason (#1632)", () => {
renderWithMantine(
<ToolsScreen
{...baseProps}
excludedTools={[
{
tool: {
name: "invalid_header_tool",
inputSchema: { type: "object" },
},
reason:
"value: x-mcp-header 'Bad Header' is not a valid RFC 9110 token",
},
]}
/>,
);
expect(screen.getByText("Excluded (SEP-2243)")).toBeInTheDocument();
expect(screen.getByText("invalid_header_tool")).toBeInTheDocument();
});
});

View file

@ -4,6 +4,7 @@ import type {
ReadResourceResult,
Tool,
} from "@modelcontextprotocol/client";
import type { ExcludedTool } from "@inspector/core/mcp/types.js";
import { ToolControls } from "../../groups/ToolControls/ToolControls";
import type { ListPaginationControlsProps } from "../../elements/ListPaginationControls/ListPaginationControls";
import {
@ -11,6 +12,7 @@ import {
type ToolProgress,
} from "../../groups/ToolDetailPanel/ToolDetailPanel";
import { ToolResultPanel } from "../../groups/ToolResultPanel/ToolResultPanel";
import { ToolCallErrorPanel } from "../../groups/ToolResultPanel/ToolCallErrorPanel";
import { resultHasResourceLinks } from "../../groups/ToolResultPanel/toolResultUtils";
import { collectSchemaDefaults, toFormSchema } from "../../../utils/jsonUtils";
@ -18,6 +20,13 @@ export interface ToolCallState {
status: "idle" | "pending" | "ok" | "error";
result?: CallToolResult;
error?: string;
/**
* JSON-RPC error code when the call REJECTED (a thrown `ProtocolError`) rather
* than resolving a result. SDK v2 rejects an unknown-tool call with `-32602`
* instead of returning an `isError` result, so this drives the distinct
* "Unknown Tool" rendering in the error panel (#1632).
*/
errorCode?: number;
progress?: ToolProgress;
}
@ -38,6 +47,9 @@ export interface ToolsUiState {
export interface ToolsScreenProps {
tools: Tool[];
/** Tools the SDK excluded from `tools/list` for invalid `x-mcp-header`
* annotations (SEP-2243), shown in the sidebar with the reason (#1632). */
excludedTools?: ExcludedTool[];
callState?: ToolCallState;
ui: ToolsUiState;
listChanged: boolean;
@ -132,6 +144,7 @@ const EmptyState = Text.withProps({
export function ToolsScreen({
tools,
excludedTools,
callState,
ui,
listChanged,
@ -157,6 +170,7 @@ export function ToolsScreen({
<SidebarCard>
<ToolControls
tools={tools}
excludedTools={excludedTools}
selectedName={selectedToolName}
searchText={search}
listChanged={listChanged}
@ -211,6 +225,19 @@ export function ToolsScreen({
/>
</ContentCard>
</ContentPane>
) : callState?.status === "error" && callState.error ? (
// A thrown rejection (no result) — e.g. SDK v2's `-32602` unknown-tool
// reject, which no longer arrives as an `isError` CallToolResult. The X
// dismisses back to the form, like a result (#1632).
<ContentPane mah={SCROLL_MAX_HEIGHT}>
<ContentCard>
<ToolCallErrorPanel
error={callState.error}
errorCode={callState.errorCode}
onClear={() => onClearResult?.()}
/>
</ContentCard>
</ContentPane>
) : selectedTool ? (
<ContentPane mah={SCROLL_MAX_HEIGHT}>
<ContentCard>

View file

@ -29,6 +29,7 @@ import type {
} from "@modelcontextprotocol/client";
import type {
ConnectionStatus,
ExcludedTool,
FetchRequestEntry,
InspectorResourceSubscription,
MessageEntry,
@ -392,6 +393,9 @@ export interface InspectorViewProps {
// Primitive lists, log streams, task state — all sourced from the
// per-primitive `useManaged*` / `useMessageLog` hooks in the parent.
tools: Tool[];
/** Tools excluded from `tools/list` for invalid `x-mcp-header` annotations
* (SEP-2243); shown in the Tools sidebar with the reason (#1632). */
excludedTools?: ExcludedTool[];
prompts: Prompt[];
resources: Resource[];
resourceTemplates: ResourceTemplate[];
@ -594,6 +598,7 @@ export function InspectorView({
initializeResult,
latencyMs,
tools,
excludedTools = [],
prompts,
resources,
resourceTemplates,
@ -1319,6 +1324,7 @@ export function InspectorView({
<ScreenStage active={activeTab === "Tools"}>
<ToolsScreen
tools={tools}
excludedTools={excludedTools}
callState={toolCallState}
ui={toolsUi}
listChanged={toolsListChanged}