diff --git a/src/vs/workbench/contrib/chat/browser/chatSelectedTools.ts b/src/vs/workbench/contrib/chat/browser/chatSelectedTools.ts
index ef3f732ed15..6bf867e7e38 100644
--- a/src/vs/workbench/contrib/chat/browser/chatSelectedTools.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatSelectedTools.ts
@@ -124,7 +124,7 @@ export class ChatSelectedTools extends Disposable {
 			let currentMap = this._sessionStates.get(currentMode.id);
 			let defaultEnablement = false;
 			if (!currentMap && currentMode.kind === ChatModeKind.Agent && currentMode.customTools) {
-				currentMap = this._toolsService.toToolAndToolSetEnablementMap(new Set(currentMode.customTools.read(r)));
+				currentMap = this._toolsService.toToolAndToolSetEnablementMap(currentMode.customTools.read(r));
 			}
 			if (!currentMap) {
 				currentMap = this._selectedTools.read(r);
diff --git a/src/vs/workbench/contrib/chat/browser/chatWidget.ts b/src/vs/workbench/contrib/chat/browser/chatWidget.ts
index dd82570e524..d6a95c8cb8d 100644
--- a/src/vs/workbench/contrib/chat/browser/chatWidget.ts
+++ b/src/vs/workbench/contrib/chat/browser/chatWidget.ts
@@ -1909,7 +1909,7 @@ export class ChatWidget extends Disposable implements IChatWidget {
 
 		// if not tools to enable are present, we are done
 		if (tools !== undefined && this.input.currentModeKind === ChatModeKind.Agent) {
-			const enablementMap = this.toolsService.toToolAndToolSetEnablementMap(new Set(tools));
+			const enablementMap = this.toolsService.toToolAndToolSetEnablementMap(tools);
 			this.input.selectedToolsModel.set(enablementMap, true);
 		}
 
diff --git a/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts b/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts
index 965f71dd31d..a13152e5427 100644
--- a/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts
+++ b/src/vs/workbench/contrib/chat/browser/languageModelToolsService.ts
@@ -484,13 +484,19 @@ export class LanguageModelToolsService extends Disposable implements ILanguageMo
 		return result;
 	}
 
-	toToolAndToolSetEnablementMap(toolOrToolSetNames: Set<string>): Map<ToolSet | IToolData, boolean> {
+	/**
+	 * Create a map that contains all tools and toolsets with their enablement state.
+	 * @param toolOrToolSetNames A list of tool or toolset names to check for enablement. If undefined, all tools and toolsets are enabled.
+	 * @returns A map of tool or toolset instances to their enablement state.
+	 */
+	toToolAndToolSetEnablementMap(enabledToolOrToolSetNames: readonly string[] | undefined): Map<ToolSet | IToolData, boolean> {
+		const toolOrToolSetNames = enabledToolOrToolSetNames ? new Set(enabledToolOrToolSetNames) : undefined;
 		const result = new Map<ToolSet | IToolData, boolean>();
 		for (const tool of this._tools.values()) {
-			result.set(tool.data, tool.data.toolReferenceName !== undefined && toolOrToolSetNames.has(tool.data.toolReferenceName));
+			result.set(tool.data, tool.data.toolReferenceName !== undefined && (toolOrToolSetNames === undefined || toolOrToolSetNames.has(tool.data.toolReferenceName)));
 		}
 		for (const toolSet of this._toolSets) {
-			result.set(toolSet, toolOrToolSetNames.has(toolSet.referenceName));
+			result.set(toolSet, (toolOrToolSetNames === undefined || toolOrToolSetNames.has(toolSet.referenceName)));
 		}
 		return result;
 	}
diff --git a/src/vs/workbench/contrib/chat/browser/promptSyntax/promptToolsCodeLensProvider.ts b/src/vs/workbench/contrib/chat/browser/promptSyntax/promptToolsCodeLensProvider.ts
index 018237936be..3d904edb187 100644
--- a/src/vs/workbench/contrib/chat/browser/promptSyntax/promptToolsCodeLensProvider.ts
+++ b/src/vs/workbench/contrib/chat/browser/promptSyntax/promptToolsCodeLensProvider.ts
@@ -78,7 +78,7 @@ class PromptToolsCodeLensProvider extends Disposable implements CodeLensProvider
 
 	private async updateTools(model: ITextModel, tools: PromptToolsMetadata) {
 
-		const selectedToolsNow = tools.value ? this.languageModelToolsService.toToolAndToolSetEnablementMap(new Set(tools.value)) : new Map();
+		const selectedToolsNow = tools.value ? this.languageModelToolsService.toToolAndToolSetEnablementMap(tools.value) : new Map();
 		const newSelectedAfter = await this.instantiationService.invokeFunction(showToolsPicker, localize('placeholder', "Select tools"), undefined, selectedToolsNow);
 		if (!newSelectedAfter) {
 			return;
diff --git a/src/vs/workbench/contrib/chat/common/languageModelToolsService.ts b/src/vs/workbench/contrib/chat/common/languageModelToolsService.ts
index be257861899..f1df32784ce 100644
--- a/src/vs/workbench/contrib/chat/common/languageModelToolsService.ts
+++ b/src/vs/workbench/contrib/chat/common/languageModelToolsService.ts
@@ -275,7 +275,7 @@ export interface ILanguageModelToolsService {
 	resetToolAutoConfirmation(): void;
 	cancelToolCallsForRequest(requestId: string): void;
 	toToolEnablementMap(toolOrToolSetNames: Set<string>): Record<string, boolean>;
-	toToolAndToolSetEnablementMap(toolOrToolSetNames: Set<string>): IToolAndToolSetEnablementMap;
+	toToolAndToolSetEnablementMap(toolOrToolSetNames: readonly string[] | undefined): IToolAndToolSetEnablementMap;
 
 	readonly toolSets: IObservable<Iterable<ToolSet>>;
 	getToolSet(id: string): ToolSet | undefined;
diff --git a/src/vs/workbench/contrib/chat/test/common/mockLanguageModelToolsService.ts b/src/vs/workbench/contrib/chat/test/common/mockLanguageModelToolsService.ts
index 511ff781e42..69bdd684bfd 100644
--- a/src/vs/workbench/contrib/chat/test/common/mockLanguageModelToolsService.ts
+++ b/src/vs/workbench/contrib/chat/test/common/mockLanguageModelToolsService.ts
@@ -76,7 +76,7 @@ export class MockLanguageModelToolsService implements ILanguageModelToolsService
 		throw new Error('Method not implemented.');
 	}
 
-	toToolAndToolSetEnablementMap(toolOrToolSetNames: Set<string>): Map<ToolSet | IToolData, boolean> {
+	toToolAndToolSetEnablementMap(toolOrToolSetNames: readonly string[] | undefined): Map<ToolSet | IToolData, boolean> {
 		throw new Error('Method not implemented.');
 	}
 }