diff --git a/src/core/mentions/index.ts b/src/core/mentions/index.ts
index 601cf4a41f..2820d2c2fb 100644
--- a/src/core/mentions/index.ts
+++ b/src/core/mentions/index.ts
@@ -248,7 +248,7 @@ async function getFileOrFolderContent(
 async function getWorkspaceProblems(cwd: string): Promise<string> {
 	// Check if diagnostics are enabled
 	const config = vscode.workspace.getConfiguration("roo-cline")
-	const includeDiagnostics = config.get<boolean>("includeDiagnostics", true)
+	const includeDiagnostics = config.get<boolean>("includeDiagnostics", false)
 
 	if (!includeDiagnostics) {
 		return "Diagnostics are disabled in settings."
diff --git a/src/core/webview/ClineProvider.ts b/src/core/webview/ClineProvider.ts
index 51f0d2f90d..240a611786 100644
--- a/src/core/webview/ClineProvider.ts
+++ b/src/core/webview/ClineProvider.ts
@@ -1443,8 +1443,8 @@ export class ClineProvider
 			maxReadFileLine: maxReadFileLine ?? -1,
 			maxConcurrentFileReads: maxConcurrentFileReads ?? 5,
 			includeDiagnostics: includeDiagnostics ?? false,
-			maxDiagnosticsCount: maxDiagnosticsCount ?? 5,
-			diagnosticsFilter: diagnosticsFilter ?? ["error", "warning"],
+			maxDiagnosticsCount: maxDiagnosticsCount ?? 50,
+			diagnosticsFilter: diagnosticsFilter ?? [],
 			settingsImportedAt: this.settingsImportedAt,
 			terminalCompressProgressBar: terminalCompressProgressBar ?? true,
 			hasSystemPromptOverride,
@@ -1597,8 +1597,8 @@ export class ClineProvider
 			maxReadFileLine: stateValues.maxReadFileLine ?? -1,
 			maxConcurrentFileReads: stateValues.maxConcurrentFileReads ?? 5,
 			includeDiagnostics: stateValues.includeDiagnostics ?? false,
-			maxDiagnosticsCount: stateValues.maxDiagnosticsCount ?? 5,
-			diagnosticsFilter: stateValues.diagnosticsFilter ?? ["error", "warning"],
+			maxDiagnosticsCount: stateValues.maxDiagnosticsCount ?? 50,
+			diagnosticsFilter: stateValues.diagnosticsFilter ?? [],
 			historyPreviewCollapsed: stateValues.historyPreviewCollapsed ?? false,
 			cloudUserInfo,
 			cloudIsAuthenticated,
diff --git a/src/core/webview/__tests__/diagnosticsSettings.integration.test.ts b/src/core/webview/__tests__/diagnosticsSettings.integration.test.ts
new file mode 100644
index 0000000000..df335767eb
--- /dev/null
+++ b/src/core/webview/__tests__/diagnosticsSettings.integration.test.ts
@@ -0,0 +1,180 @@
+import * as vscode from "vscode"
+import { ClineProvider } from "../ClineProvider"
+import { ContextProxy } from "../../config/ContextProxy"
+
+// Mock vscode
+jest.mock("vscode", () => ({
+	workspace: {
+		getConfiguration: jest.fn(() => ({
+			get: jest.fn(),
+		})),
+	},
+	ExtensionContext: jest.fn(),
+	OutputChannel: jest.fn(),
+	Uri: {
+		file: jest.fn((path: string) => ({ fsPath: path })),
+	},
+	ExtensionMode: {
+		Development: 1,
+		Production: 2,
+		Test: 3,
+	},
+}))
+
+// Mock other dependencies
+jest.mock("../../config/ContextProxy")
+jest.mock("../../../services/code-index/manager")
+jest.mock("../../../services/mcp/McpServerManager")
+jest.mock("../../config/CustomModesManager")
+jest.mock("../../../services/marketplace/MarketplaceManager")
+
+describe("Diagnostics Settings Integration", () => {
+	let provider: ClineProvider
+	let mockContext: any
+	let mockOutputChannel: any
+	let mockContextProxy: jest.Mocked<ContextProxy>
+
+	beforeEach(() => {
+		// Setup mocks
+		mockContext = {
+			globalState: {
+				get: jest.fn(),
+				update: jest.fn(),
+				keys: jest.fn(() => []),
+			},
+			secrets: {
+				get: jest.fn(),
+				store: jest.fn(),
+			},
+			globalStorageUri: { fsPath: "/test/storage" },
+			extensionUri: { fsPath: "/test/extension" },
+			extension: {
+				packageJSON: {
+					version: "1.0.0",
+					name: "test-extension",
+				},
+			},
+		}
+
+		mockOutputChannel = {
+			appendLine: jest.fn(),
+		}
+
+		mockContextProxy = {
+			getValue: jest.fn(),
+			setValue: jest.fn(),
+			getValues: jest.fn(() => ({
+				includeDiagnostics: false,
+				maxDiagnosticsCount: 50,
+				diagnosticsFilter: [],
+			})),
+			setValues: jest.fn(),
+			getProviderSettings: jest.fn(() => ({})),
+			setProviderSettings: jest.fn(),
+			resetAllState: jest.fn(),
+			extensionUri: { fsPath: "/test/extension" },
+			globalStorageUri: { fsPath: "/test/storage" },
+			extensionMode: vscode.ExtensionMode.Test,
+		} as any
+
+		// Create provider instance
+		provider = new ClineProvider(mockContext, mockOutputChannel, "sidebar", mockContextProxy)
+	})
+
+	afterEach(() => {
+		jest.clearAllMocks()
+	})
+
+	describe("Settings Persistence", () => {
+		it("should persist includeDiagnostics setting", async () => {
+			// Simulate setting update
+			await provider.setValue("includeDiagnostics", true)
+
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("includeDiagnostics", true)
+		})
+
+		it("should persist maxDiagnosticsCount setting", async () => {
+			// Simulate setting update
+			await provider.setValue("maxDiagnosticsCount", 100)
+
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("maxDiagnosticsCount", 100)
+		})
+
+		it("should persist diagnosticsFilter setting", async () => {
+			// Simulate setting update
+			const filters = ["eslint", "typescript"]
+			await provider.setValue("diagnosticsFilter", filters)
+
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("diagnosticsFilter", filters)
+		})
+
+		it("should retrieve diagnostics settings from state", () => {
+			// Setup mock return values
+			mockContextProxy.getValue.mockImplementation((key: string) => {
+				const values: Record<string, any> = {
+					includeDiagnostics: true,
+					maxDiagnosticsCount: 75,
+					diagnosticsFilter: ["error", "warning"],
+				}
+				return values[key]
+			})
+
+			// Retrieve settings
+			const includeDiagnostics = provider.getValue("includeDiagnostics")
+			const maxDiagnosticsCount = provider.getValue("maxDiagnosticsCount")
+			const diagnosticsFilter = provider.getValue("diagnosticsFilter")
+
+			expect(includeDiagnostics).toBe(true)
+			expect(maxDiagnosticsCount).toBe(75)
+			expect(diagnosticsFilter).toEqual(["error", "warning"])
+		})
+
+		it("should update multiple diagnostics settings at once", async () => {
+			const newSettings = {
+				includeDiagnostics: true,
+				maxDiagnosticsCount: 100,
+				diagnosticsFilter: ["eslint/no-unused-vars", "typescript"],
+			}
+
+			await provider.setValues(newSettings as any)
+
+			expect(mockContextProxy.setValues).toHaveBeenCalledWith(expect.objectContaining(newSettings))
+		})
+	})
+
+	describe("Default Values", () => {
+		it("should use correct default values when settings are undefined", () => {
+			mockContextProxy.getValue.mockReturnValue(undefined)
+			mockContextProxy.getValues.mockReturnValue({})
+
+			const state = provider.getValues()
+
+			// These defaults should match what's in the code
+			expect(state.includeDiagnostics ?? false).toBe(false)
+			expect(state.maxDiagnosticsCount ?? 50).toBe(50)
+			expect(state.diagnosticsFilter ?? []).toEqual([])
+		})
+	})
+
+	describe("Settings Validation", () => {
+		it("should validate maxDiagnosticsCount range", async () => {
+			// Test valid range
+			await provider.setValue("maxDiagnosticsCount", 100)
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("maxDiagnosticsCount", 100)
+
+			// Note: Validation should be done in the UI component
+			// The provider itself doesn't validate ranges
+		})
+
+		it("should handle empty diagnosticsFilter", async () => {
+			await provider.setValue("diagnosticsFilter", [])
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("diagnosticsFilter", [])
+		})
+
+		it("should handle diagnosticsFilter with multiple values", async () => {
+			const filters = ["eslint", "typescript", "dart Error", "custom-linter"]
+			await provider.setValue("diagnosticsFilter", filters)
+			expect(mockContextProxy.setValue).toHaveBeenCalledWith("diagnosticsFilter", filters)
+		})
+	})
+})
diff --git a/src/integrations/diagnostics/__tests__/diagnosticsToProblemsString.test.ts b/src/integrations/diagnostics/__tests__/diagnosticsToProblemsString.test.ts
new file mode 100644
index 0000000000..e546f7d0c4
--- /dev/null
+++ b/src/integrations/diagnostics/__tests__/diagnosticsToProblemsString.test.ts
@@ -0,0 +1,198 @@
+import * as vscode from "vscode"
+import { diagnosticsToProblemsString } from "../index"
+
+// Mock vscode
+jest.mock("vscode", () => ({
+	workspace: {
+		getConfiguration: jest.fn(() => ({
+			get: jest.fn((key: string, defaultValue: any) => {
+				const config: Record<string, any> = {
+					includeDiagnostics: false,
+					maxDiagnosticsCount: 50,
+					diagnosticsFilter: [],
+				}
+				return config[key] ?? defaultValue
+			}),
+		})),
+		fs: {
+			stat: jest.fn(),
+		},
+		openTextDocument: jest.fn(),
+	},
+	DiagnosticSeverity: {
+		Error: 0,
+		Warning: 1,
+		Information: 2,
+		Hint: 3,
+	},
+	FileType: {
+		File: 1,
+		Directory: 2,
+	},
+	Uri: {
+		file: (path: string) => ({ fsPath: path }),
+	},
+	Range: jest.fn((startLine: number, startChar: number, endLine: number, endChar: number) => ({
+		start: { line: startLine, character: startChar },
+		end: { line: endLine, character: endChar },
+	})),
+	Position: jest.fn((line: number, char: number) => ({ line, character: char })),
+}))
+
+describe("diagnosticsToProblemsString", () => {
+	const mockCwd = "/test/workspace"
+
+	beforeEach(() => {
+		jest.clearAllMocks()
+	})
+
+	it("should return empty string when includeDiagnostics is false", async () => {
+		const diagnostics: [vscode.Uri, vscode.Diagnostic[]][] = [
+			[
+				vscode.Uri.file("/test/workspace/file.ts"),
+				[
+					{
+						range: new vscode.Range(0, 0, 0, 10),
+						message: "Test error",
+						severity: vscode.DiagnosticSeverity.Error,
+					} as vscode.Diagnostic,
+				],
+			],
+		]
+
+		const result = await diagnosticsToProblemsString(diagnostics, [vscode.DiagnosticSeverity.Error], mockCwd, {
+			includeDiagnostics: false,
+		})
+
+		expect(result).toBe("")
+	})
+
+	it("should include diagnostics when includeDiagnostics is true", async () => {
+		const mockDocument = {
+			lineAt: jest.fn(() => ({ text: "const x = 1" })),
+		}
+		;(vscode.workspace.openTextDocument as jest.Mock).mockResolvedValue(mockDocument)
+		;(vscode.workspace.fs.stat as jest.Mock).mockResolvedValue({ type: vscode.FileType.File })
+
+		const diagnostics: [vscode.Uri, vscode.Diagnostic[]][] = [
+			[
+				vscode.Uri.file("/test/workspace/file.ts"),
+				[
+					{
+						range: new vscode.Range(0, 0, 0, 10),
+						message: "Test error",
+						severity: vscode.DiagnosticSeverity.Error,
+						source: "typescript",
+					} as vscode.Diagnostic,
+				],
+			],
+		]
+
+		const result = await diagnosticsToProblemsString(diagnostics, [vscode.DiagnosticSeverity.Error], mockCwd, {
+			includeDiagnostics: true,
+		})
+
+		expect(result).toContain("file.ts")
+		expect(result).toContain("Test error")
+		expect(result).toContain("typescript")
+	})
+
+	it("should respect maxDiagnosticsCount", async () => {
+		const mockDocument = {
+			lineAt: jest.fn(() => ({ text: "const x = 1" })),
+		}
+		;(vscode.workspace.openTextDocument as jest.Mock).mockResolvedValue(mockDocument)
+		;(vscode.workspace.fs.stat as jest.Mock).mockResolvedValue({ type: vscode.FileType.File })
+
+		const diagnostics: [vscode.Uri, vscode.Diagnostic[]][] = [
+			[
+				vscode.Uri.file("/test/workspace/file.ts"),
+				Array(10)
+					.fill(null)
+					.map(
+						(_, i) =>
+							({
+								range: new vscode.Range(i, 0, i, 10),
+								message: `Test error ${i}`,
+								severity: vscode.DiagnosticSeverity.Error,
+							}) as vscode.Diagnostic,
+					),
+			],
+		]
+
+		const result = await diagnosticsToProblemsString(diagnostics, [vscode.DiagnosticSeverity.Error], mockCwd, {
+			includeDiagnostics: true,
+			maxDiagnosticsCount: 3,
+		})
+
+		expect(result).toContain("Test error 0")
+		expect(result).toContain("Test error 1")
+		expect(result).toContain("Test error 2")
+		expect(result).not.toContain("Test error 3")
+		expect(result).toContain("7 more diagnostics omitted")
+	})
+
+	it("should apply diagnosticsFilter correctly", async () => {
+		const mockDocument = {
+			lineAt: jest.fn(() => ({ text: "const x = 1" })),
+		}
+		;(vscode.workspace.openTextDocument as jest.Mock).mockResolvedValue(mockDocument)
+		;(vscode.workspace.fs.stat as jest.Mock).mockResolvedValue({ type: vscode.FileType.File })
+
+		const diagnostics: [vscode.Uri, vscode.Diagnostic[]][] = [
+			[
+				vscode.Uri.file("/test/workspace/file.ts"),
+				[
+					{
+						range: new vscode.Range(0, 0, 0, 10),
+						message: "ESLint error",
+						severity: vscode.DiagnosticSeverity.Error,
+						source: "eslint",
+						code: "no-unused-vars",
+					} as vscode.Diagnostic,
+					{
+						range: new vscode.Range(1, 0, 1, 10),
+						message: "TypeScript error",
+						severity: vscode.DiagnosticSeverity.Error,
+						source: "typescript",
+						code: "2322",
+					} as vscode.Diagnostic,
+				],
+			],
+		]
+
+		const result = await diagnosticsToProblemsString(diagnostics, [vscode.DiagnosticSeverity.Error], mockCwd, {
+			includeDiagnostics: true,
+			diagnosticsFilter: ["typescript 2322"],
+		})
+
+		expect(result).toContain("TypeScript error")
+		expect(result).not.toContain("ESLint error")
+	})
+
+	it("should handle file read errors gracefully", async () => {
+		;(vscode.workspace.openTextDocument as jest.Mock).mockRejectedValue(new Error("File not found"))
+		;(vscode.workspace.fs.stat as jest.Mock).mockResolvedValue({ type: vscode.FileType.File })
+
+		const diagnostics: [vscode.Uri, vscode.Diagnostic[]][] = [
+			[
+				vscode.Uri.file("/test/workspace/file.ts"),
+				[
+					{
+						range: new vscode.Range(0, 0, 0, 10),
+						message: "Test error",
+						severity: vscode.DiagnosticSeverity.Error,
+					} as vscode.Diagnostic,
+				],
+			],
+		]
+
+		const result = await diagnosticsToProblemsString(diagnostics, [vscode.DiagnosticSeverity.Error], mockCwd, {
+			includeDiagnostics: true,
+		})
+
+		expect(result).toContain("file.ts")
+		expect(result).toContain("(unavailable)")
+		expect(result).toContain("Test error")
+	})
+})
diff --git a/src/integrations/diagnostics/index.ts b/src/integrations/diagnostics/index.ts
index 0765f630a6..df4d139183 100644
--- a/src/integrations/diagnostics/index.ts
+++ b/src/integrations/diagnostics/index.ts
@@ -81,20 +81,15 @@ export async function diagnosticsToProblemsString(
 	},
 ): Promise<string> {
 	// Use provided options or fall back to VSCode configuration
-	const includeDiagnostics =
-		options?.includeDiagnostics ??
-		vscode.workspace.getConfiguration("roo-cline").get<boolean>("includeDiagnostics", false)
+	const config = vscode.workspace.getConfiguration("roo-cline")
+	const includeDiagnostics = options?.includeDiagnostics ?? config.get<boolean>("includeDiagnostics", false)
 
 	if (!includeDiagnostics) {
 		return ""
 	}
 
-	const maxDiagnosticsCount =
-		options?.maxDiagnosticsCount ??
-		vscode.workspace.getConfiguration("roo-cline").get<number>("maxDiagnosticsCount", 5)
-	const diagnosticsFilter =
-		options?.diagnosticsFilter ??
-		vscode.workspace.getConfiguration("roo-cline").get<string[]>("diagnosticsFilter", ["error", "warning"])
+	const maxDiagnosticsCount = options?.maxDiagnosticsCount ?? config.get<number>("maxDiagnosticsCount", 50)
+	const diagnosticsFilter = options?.diagnosticsFilter ?? config.get<string[]>("diagnosticsFilter", [])
 
 	const documents = new Map<vscode.Uri, vscode.TextDocument>()
 	const fileStats = new Map<vscode.Uri, vscode.FileStat>()
@@ -112,10 +107,10 @@ export async function diagnosticsToProblemsString(
 				const code = typeof d.code === "object" ? d.code.value : d.code
 				const filterKey = source ? `${source} ${code || ""}`.trim() : `${code || ""}`.trim()
 
-				// Check if this diagnostic should be filtered out
-				return !diagnosticsFilter.some((filter) => {
-					// Support partial matching
-					return filterKey.includes(filter) || d.message.includes(filter)
+				// Check if this diagnostic matches any filter (exact match)
+				return diagnosticsFilter.some((filter) => {
+					// Exact matching for filter key
+					return filterKey === filter || (filter && filterKey.startsWith(filter + " "))
 				})
 			})
 			.sort((a, b) => a.range.start.line - b.range.start.line)
diff --git a/src/package.json b/src/package.json
index 77ce1a1240..8212f3da17 100644
--- a/src/package.json
+++ b/src/package.json
@@ -3,7 +3,7 @@
 	"displayName": "%extension.displayName%",
 	"description": "%extension.description%",
 	"publisher": "RooVeterinaryInc",
-	"version": "3.20.3",
+	"version": "3.20.4",
 	"icon": "assets/icons/icon.png",
 	"galleryBanner": {
 		"color": "#617A91",
@@ -347,7 +347,7 @@
 				},
 				"roo-cline.includeDiagnostics": {
 					"type": "boolean",
-					"default": true,
+					"default": false,
 					"description": "%settings.includeDiagnostics.description%"
 				},
 				"roo-cline.maxDiagnosticsCount": {
diff --git a/webview-ui/src/components/settings/DiagnosticsSettings.tsx b/webview-ui/src/components/settings/DiagnosticsSettings.tsx
index bfe3f2173f..51ae94a65e 100644
--- a/webview-ui/src/components/settings/DiagnosticsSettings.tsx
+++ b/webview-ui/src/components/settings/DiagnosticsSettings.tsx
@@ -1,4 +1,4 @@
-import { HTMLAttributes } from "react"
+import { HTMLAttributes, ChangeEvent } from "react"
 import { useAppTranslation } from "@/i18n/TranslationContext"
 import { VSCodeCheckbox } from "@vscode/webview-ui-toolkit/react"
 import { AlertCircle } from "lucide-react"
@@ -48,7 +48,9 @@ export const DiagnosticsSettings = ({
 				<div>
 					<VSCodeCheckbox
 						checked={includeDiagnostics}
-						onChange={(e: any) => setCachedStateField("includeDiagnostics", e.target.checked)}
+						onChange={(e: ChangeEvent<HTMLInputElement>) =>
+							setCachedStateField("includeDiagnostics", e.target.checked)
+						}
 						data-testid="include-diagnostics-checkbox">
 						<label className="block font-medium mb-1">
 							{t("settings:diagnostics.includeDiagnostics.label")}
@@ -71,7 +73,11 @@ export const DiagnosticsSettings = ({
 									max={200}
 									step={1}
 									value={[maxDiagnosticsCount ?? 50]}
-									onValueChange={([value]) => setCachedStateField("maxDiagnosticsCount", value)}
+									onValueChange={([value]) => {
+										if (value >= 0 && value <= 200) {
+											setCachedStateField("maxDiagnosticsCount", value)
+										}
+									}}
 									data-testid="max-diagnostics-count-slider"
 								/>
 								<span className="w-10">{maxDiagnosticsCount ?? 50}</span>
diff --git a/webview-ui/src/components/settings/SettingsView.tsx b/webview-ui/src/components/settings/SettingsView.tsx
index 5a330c8996..a383b5142c 100644
--- a/webview-ui/src/components/settings/SettingsView.tsx
+++ b/webview-ui/src/components/settings/SettingsView.tsx
@@ -64,6 +64,7 @@ import { LanguageSettings } from "./LanguageSettings"
 import { About } from "./About"
 import { Section } from "./Section"
 import PromptsSettings from "./PromptsSettings"
+import { DiagnosticsSettings } from "./DiagnosticsSettings"
 import { cn } from "@/lib/utils"
 
 export const settingsTabsContainer = "flex flex-1 overflow-hidden [&.narrow_.tab-label]:hidden"
@@ -84,6 +85,7 @@ const sectionNames = [
 	"checkpoints",
 	"notifications",
 	"contextManagement",
+	"diagnostics",
 	"terminal",
 	"prompts",
 	"experimental",
@@ -172,6 +174,9 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 		codebaseIndexConfig,
 		codebaseIndexModels,
 		customSupportPrompts,
+		includeDiagnostics,
+		maxDiagnosticsCount,
+		diagnosticsFilter,
 	} = cachedState
 
 	const apiConfiguration = useMemo(() => cachedState.apiConfiguration ?? {}, [cachedState.apiConfiguration])
@@ -315,6 +320,9 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 			vscode.postMessage({ type: "upsertApiConfiguration", text: currentApiConfigName, apiConfiguration })
 			vscode.postMessage({ type: "telemetrySetting", text: telemetrySetting })
 			vscode.postMessage({ type: "codebaseIndexConfig", values: codebaseIndexConfig })
+			vscode.postMessage({ type: "includeDiagnostics", bool: includeDiagnostics })
+			vscode.postMessage({ type: "maxDiagnosticsCount", value: maxDiagnosticsCount })
+			vscode.postMessage({ type: "diagnosticsFilter", values: diagnosticsFilter })
 			setChangeDetected(false)
 		}
 	}
@@ -390,6 +398,7 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 			{ id: "checkpoints", icon: GitBranch },
 			{ id: "notifications", icon: Bell },
 			{ id: "contextManagement", icon: Database },
+			{ id: "diagnostics", icon: AlertTriangle },
 			{ id: "terminal", icon: SquareTerminal },
 			{ id: "prompts", icon: MessageSquare },
 			{ id: "experimental", icon: FlaskConical },
@@ -648,6 +657,16 @@ const SettingsView = forwardRef<SettingsViewRef, SettingsViewProps>(({ onDone, t
 						/>
 					)}
 
+					{/* Diagnostics Section */}
+					{activeTab === "diagnostics" && (
+						<DiagnosticsSettings
+							includeDiagnostics={includeDiagnostics}
+							maxDiagnosticsCount={maxDiagnosticsCount}
+							diagnosticsFilter={diagnosticsFilter}
+							setCachedStateField={setCachedStateField}
+						/>
+					)}
+
 					{/* Terminal Section */}
 					{activeTab === "terminal" && (
 						<TerminalSettings
diff --git a/webview-ui/src/components/settings/__tests__/DiagnosticsSettings.test.tsx b/webview-ui/src/components/settings/__tests__/DiagnosticsSettings.test.tsx
new file mode 100644
index 0000000000..39a64c94f6
--- /dev/null
+++ b/webview-ui/src/components/settings/__tests__/DiagnosticsSettings.test.tsx
@@ -0,0 +1,182 @@
+import React from "react"
+import { render, screen, fireEvent } from "@testing-library/react"
+import "@testing-library/jest-dom"
+import { DiagnosticsSettings } from "../DiagnosticsSettings"
+
+// Mock the translation hook
+jest.mock("@src/i18n/TranslationContext", () => ({
+	useAppTranslation: () => ({
+		t: (key: string) => key,
+	}),
+}))
+
+// Mock VSCode components
+jest.mock("@vscode/webview-ui-toolkit/react", () => ({
+	VSCodeCheckbox: ({ children, onChange, checked, ...props }: any) => (
+		<label>
+			<input type="checkbox" checked={checked} onChange={onChange} {...props} />
+			{children}
+		</label>
+	),
+}))
+
+// Mock Slider component
+jest.mock("@src/components/ui/slider", () => ({
+	Slider: ({ value, onValueChange, min, max, ...props }: any) => (
+		<input
+			type="range"
+			value={value?.[0] || 0}
+			onChange={(e) => onValueChange([parseInt(e.target.value)])}
+			min={min}
+			max={max}
+			{...props}
+		/>
+	),
+}))
+
+// Mock Input component
+jest.mock("@src/components/ui/input", () => ({
+	Input: (props: any) => <input {...props} />,
+}))
+
+// Mock SectionHeader component
+jest.mock("../SectionHeader", () => ({
+	SectionHeader: ({ children, description }: any) => (
+		<div>
+			<div>{children}</div>
+			{description && <div>{description}</div>}
+		</div>
+	),
+}))
+
+// Mock Section component
+jest.mock("../Section", () => ({
+	Section: ({ children }: any) => <div>{children}</div>,
+}))
+
+describe("DiagnosticsSettings", () => {
+	const mockSetCachedStateField = jest.fn()
+
+	const defaultProps = {
+		includeDiagnostics: false,
+		maxDiagnosticsCount: 50,
+		diagnosticsFilter: ["error", "warning"],
+		setCachedStateField: mockSetCachedStateField,
+	}
+
+	beforeEach(() => {
+		jest.clearAllMocks()
+	})
+
+	it("renders all diagnostic settings", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		expect(screen.getByText("settings:sections.diagnostics")).toBeInTheDocument()
+		expect(screen.getByText("settings:diagnostics.description")).toBeInTheDocument()
+		expect(screen.getByTestId("include-diagnostics-checkbox")).toBeInTheDocument()
+		expect(screen.getByTestId("max-diagnostics-count-slider")).toBeInTheDocument()
+		expect(screen.getByTestId("diagnostics-filter-input")).toBeInTheDocument()
+	})
+
+	it("displays current values correctly", () => {
+		render(<DiagnosticsSettings {...defaultProps} includeDiagnostics={true} />)
+
+		const checkbox = screen.getByTestId("include-diagnostics-checkbox") as HTMLInputElement
+		expect(checkbox.checked).toBe(true)
+
+		const slider = screen.getByTestId("max-diagnostics-count-slider") as HTMLInputElement
+		expect(slider.value).toBe("50")
+
+		const filterInput = screen.getByTestId("diagnostics-filter-input") as HTMLInputElement
+		expect(filterInput.value).toBe("error, warning")
+	})
+
+	it("calls setCachedStateField when checkbox is toggled", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const checkbox = screen.getByTestId("include-diagnostics-checkbox")
+		fireEvent.change(checkbox, { target: { checked: true } })
+
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("includeDiagnostics", true)
+	})
+
+	it("calls setCachedStateField when slider value changes", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const slider = screen.getByTestId("max-diagnostics-count-slider")
+		fireEvent.change(slider, { target: { value: "75" } })
+
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("maxDiagnosticsCount", 75)
+	})
+
+	it("validates slider value range", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const slider = screen.getByTestId("max-diagnostics-count-slider")
+
+		// Test value above max
+		fireEvent.change(slider, { target: { value: "250" } })
+		expect(mockSetCachedStateField).not.toHaveBeenCalledWith("maxDiagnosticsCount", 250)
+
+		// Test negative value
+		fireEvent.change(slider, { target: { value: "-10" } })
+		expect(mockSetCachedStateField).not.toHaveBeenCalledWith("maxDiagnosticsCount", -10)
+
+		// Test valid value
+		fireEvent.change(slider, { target: { value: "100" } })
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("maxDiagnosticsCount", 100)
+	})
+
+	it("calls setCachedStateField when filter input changes", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const filterInput = screen.getByTestId("diagnostics-filter-input")
+		fireEvent.change(filterInput, { target: { value: "eslint, typescript" } })
+
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("diagnosticsFilter", ["eslint", "typescript"])
+	})
+
+	it("handles empty filter input", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const filterInput = screen.getByTestId("diagnostics-filter-input")
+		fireEvent.change(filterInput, { target: { value: "" } })
+
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("diagnosticsFilter", [])
+	})
+
+	it("trims whitespace from filter values", () => {
+		render(<DiagnosticsSettings {...defaultProps} />)
+
+		const filterInput = screen.getByTestId("diagnostics-filter-input")
+		fireEvent.change(filterInput, { target: { value: "  eslint  ,  typescript  " } })
+
+		expect(mockSetCachedStateField).toHaveBeenCalledWith("diagnosticsFilter", ["eslint", "typescript"])
+	})
+
+	it("renders with undefined props", () => {
+		render(<DiagnosticsSettings setCachedStateField={mockSetCachedStateField} />)
+
+		const checkbox = screen.getByTestId("include-diagnostics-checkbox") as HTMLInputElement
+		expect(checkbox.checked).toBe(false)
+
+		const slider = screen.getByTestId("max-diagnostics-count-slider") as HTMLInputElement
+		expect(slider.value).toBe("50")
+
+		const filterInput = screen.getByTestId("diagnostics-filter-input") as HTMLInputElement
+		expect(filterInput.value).toBe("")
+	})
+
+	it("displays correct count value next to slider", () => {
+		render(<DiagnosticsSettings {...defaultProps} maxDiagnosticsCount={75} />)
+
+		expect(screen.getByText("75")).toBeInTheDocument()
+	})
+
+	it("applies custom className", () => {
+		const { container } = render(<DiagnosticsSettings {...defaultProps} className="custom-class" />)
+
+		const rootElement = container.firstChild as HTMLElement
+		expect(rootElement).toHaveClass("custom-class")
+	})
+})
diff --git a/webview-ui/src/i18n/locales/en/settings.json b/webview-ui/src/i18n/locales/en/settings.json
index b7f2a014c9..d28309f254 100644
--- a/webview-ui/src/i18n/locales/en/settings.json
+++ b/webview-ui/src/i18n/locales/en/settings.json
@@ -27,6 +27,7 @@
 		"checkpoints": "Checkpoints",
 		"notifications": "Notifications",
 		"contextManagement": "Context",
+		"diagnostics": "Diagnostics",
 		"terminal": "Terminal",
 		"prompts": "Prompts",
 		"experimental": "Experimental",
@@ -395,6 +396,21 @@
 			"always_full_read": "Always read entire file"
 		}
 	},
+	"diagnostics": {
+		"description": "Configure how workspace diagnostics (errors and warnings) are included in the AI's context",
+		"includeDiagnostics": {
+			"label": "Include diagnostics in context",
+			"description": "When enabled, workspace errors and warnings will be included when using @problems mention"
+		},
+		"maxDiagnosticsCount": {
+			"label": "Maximum diagnostics count",
+			"description": "Limit the number of diagnostics included to prevent excessive token usage"
+		},
+		"diagnosticsFilter": {
+			"label": "Diagnostics filter",
+			"description": "Filter diagnostics by source and code (e.g., 'eslint', 'typescript', 'dart Error'). Leave empty to include all diagnostics"
+		}
+	},
 	"terminal": {
 		"basic": {
 			"label": "Terminal Settings: Basic",