feat: remove MCP SERVERS section from system prompt

apps/cli/README.md

@@ -149,8 +149,8 @@ Tokens are valid for 90 days. The CLI will prompt you to re-authenticate when yo
 
 | Option                            | Description                                                                             | Default                       |
 | --------------------------------- | --------------------------------------------------------------------------------------- | ----------------------------- |
-| `[prompt]` | Your prompt (positional argument, optional) | None |
-| `-w, --workspace <path>` | Workspace path to operate in | Current directory |
+| `[prompt]`                        | Your prompt (positional argument, optional)                                             | None                          |
+| `-w, --workspace <path>`          | Workspace path to operate in                                                            | Current directory             |
 | `-e, --extension <path>`          | Path to the extension bundle directory                                                  | Auto-detected                 |
 | `-d, --debug`                     | Enable debug output (includes detailed debug information, prompts, paths, etc)          | `false`                       |
 | `-x, --exit-on-complete`          | Exit the process when task completes (useful for testing)                               | `false`                       |

src/core/prompts/__tests__/add-custom-instructions.spec.ts

@@ -242,31 +242,6 @@ describe("addCustomInstructions", () => {
 		expect(prompt).toMatchFileSnapshot("./__snapshots__/add-custom-instructions/ask-mode-prompt.snap")
 	})
 
-	it("should include MCP server creation info when enabled", async () => {
-		const mockMcpHub = createMockMcpHub(true)
-
-		const prompt = await SYSTEM_PROMPT(
-			mockContext,
-			"/test/path",
-			false, // supportsImages
-			mockMcpHub, // mcpHub
-			undefined, // diffStrategy
-			undefined, // browserViewportSize
-			defaultModeSlug, // mode
-			undefined, // customModePrompts
-			undefined, // customModes,
-			undefined, // globalCustomInstructions
-			undefined, // experiments
-			true, // enableMcpServerCreation
-			undefined, // language
-			undefined, // rooIgnoreInstructions
-			undefined, // partialReadsEnabled
-		)
-
-		expect(prompt).toContain("Creating an MCP Server")
-		expect(prompt).toMatchFileSnapshot("./__snapshots__/add-custom-instructions/mcp-server-creation-enabled.snap")
-	})
-
 	it("should exclude MCP server creation info when disabled", async () => {
 		const mockMcpHub = createMockMcpHub(false)
 

src/core/prompts/sections/index.ts

@@ -3,7 +3,6 @@ export { getSystemInfoSection } from "./system-info"
 export { getObjectiveSection } from "./objective"
 export { addCustomInstructions } from "./custom-instructions"
 export { getSharedToolUseSection } from "./tool-use"
-export { getMcpServersSection } from "./mcp-servers"
 export { getToolUseGuidelinesSection } from "./tool-use-guidelines"
 export { getCapabilitiesSection } from "./capabilities"
 export { getModesSection } from "./modes"

src/core/prompts/system.ts

@@ -20,7 +20,6 @@ import {
 	getSystemInfoSection,
 	getObjectiveSection,
 	getSharedToolUseSection,
-	getMcpServersSection,
 	getToolUseGuidelinesSection,
 	getCapabilitiesSection,
 	getModesSection,
@@ -78,11 +77,11 @@ async function generatePrompt(
 
 	const codeIndexManager = CodeIndexManager.getInstance(context, cwd)
 
-	const [modesSection, mcpServersSection, skillsSection] = await Promise.all([
+	// Tool calling is native-only.
+	const effectiveProtocol = "native"
+
+	const [modesSection, skillsSection] = await Promise.all([
 		getModesSection(context),
-		shouldIncludeMcp
-			? getMcpServersSection(mcpHub, diffStrategy, enableMcpServerCreation, false)
-			: Promise.resolve(""),
 		getSkillsSection(skillsManager, mode as string),
 	])
 
@@ -97,8 +96,6 @@ ${getSharedToolUseSection(experiments)}${toolsCatalog}
 
  ${getToolUseGuidelinesSection(experiments)}
 
-${mcpServersSection}
-
 ${getCapabilitiesSection(cwd, shouldIncludeMcp ? mcpHub : undefined)}
 
 ${modesSection}

src/core/tools/__tests__/useMcpToolTool.spec.ts

@@ -611,6 +611,11 @@ describe("useMcpToolTool", () => {
 					tool_name: "get_user_profile", // Model mangled hyphens to underscores
 					arguments: "{}",
 				},
+				nativeArgs: {
+					server_name: "test-server",
+					tool_name: "get_user_profile", // Model mangled hyphens to underscores
+					arguments: {},
+				},
 				partial: false,
 			}
 
@@ -620,8 +625,6 @@ describe("useMcpToolTool", () => {
 				askApproval: mockAskApproval,
 				handleError: mockHandleError,
 				pushToolResult: mockPushToolResult,
-				removeClosingTag: mockRemoveClosingTag,
-				toolProtocol: "xml",
 			})
 
 			// Tool should be found and executed