Add confirmation dialog to switch agent tool

package.json

@@ -1086,10 +1086,16 @@
 							"enum": [
 								"Plan"
 							]
+						},
+						"explainer": {
+							"type": "string",
+							"maxLength": 120,
+							"description": "A short user-facing explainer for benefits of switching (max 12 words). Shown in a confirmation dialog, so do not repeat it in your response."
 						}
 					},
 					"required": [
-						"agentName"
+						"agentName",
+						"explainer"
 					]
 				}
 			},
@@ -3324,6 +3330,15 @@
 							"onExp"
 						]
 					},
+					"github.copilot.chat.switchAgent.confirm": {
+						"type": "boolean",
+						"default": true,
+						"markdownDescription": "%github.copilot.config.switchAgent.confirm%",
+						"tags": [
+							"experimental",
+							"onExp"
+						]
+					},
 					"github.copilot.chat.imageUpload.enabled": {
 						"type": "boolean",
 						"default": true,

package.nls.json

@@ -354,6 +354,7 @@
 	"github.copilot.config.anthropic.tools.websearch.blockedDomains": "List of domains to exclude from web search results (e.g., `[\"untrustedsource.com\"]`). Domains should not include the HTTP/HTTPS scheme. Subdomains are automatically excluded. Cannot be used together with allowed domains.",
 	"github.copilot.config.anthropic.tools.websearch.userLocation": "User location for personalizing web search results based on geographic context. All fields (city, region, country, timezone) are optional. Example: `{\"city\": \"San Francisco\", \"region\": \"California\", \"country\": \"US\", \"timezone\": \"America/Los_Angeles\"}`",
 	"github.copilot.config.switchAgent.enabled": "Allow agent to switch to the Plan agent for research, exploration, and planning tasks.",
+	"github.copilot.config.switchAgent.confirm": "Show a confirmation dialog before switching to a different agent.",
 	"github.copilot.config.completionsFetcher": "Sets the fetcher used for the inline completions.",
 	"github.copilot.config.nesFetcher": "Sets the fetcher used for the next edit suggestions.",
 	"github.copilot.config.debug.overrideChatEngine": "Override the chat model. This allows you to test with different models.\n\n**Note**: This is an advanced debugging setting and should not be used while self-hosting as it may lead to a different experience compared to end-users.",

src/extension/tools/vscode-node/switchAgentTool.ts

@@ -12,6 +12,7 @@ import { ICopilotTool, ToolRegistry } from '../common/toolsRegistry';
 
 interface ISwitchAgentParams {
 	agentName: string;
+	explainer: string;
 }
 
 export class SwitchAgentTool implements ICopilotTool<ISwitchAgentParams> {
@@ -46,9 +47,17 @@ export class SwitchAgentTool implements ICopilotTool<ISwitchAgentParams> {
 			throw new Error(vscode.l10n.t('Only "Plan" agent is supported. Received: "{0}"', agentName));
 		}
 
+		const confirmationEnabled = vscode.workspace.getConfiguration('github.copilot.chat').get<boolean>('switchAgent.confirm', true);
+		const explainer = options.input.explainer?.trim();
 		return {
 			invocationMessage: new MarkdownString(vscode.l10n.t('Switching to {0} agent', agentName)),
-			pastTenseMessage: new MarkdownString(vscode.l10n.t('Switched to {0} agent', agentName))
+			pastTenseMessage: new MarkdownString(vscode.l10n.t('Switched to {0} agent', agentName)),
+			...confirmationEnabled && explainer ? {
+				confirmationMessages: {
+					title: vscode.l10n.t('Switch to {0} Agent', agentName),
+					message: new MarkdownString().appendText(explainer),
+				},
+			} : {},
 		};
 	}
 }

src/platform/configuration/common/configurationService.ts

@@ -984,6 +984,7 @@ export namespace ConfigKey {
 	export const CloudAgentEnabled = defineSetting<boolean>('chat.cloudAgent.enabled', ConfigType.Simple, true);
 	export const AdditionalReadAccessPaths = defineSetting<string[]>('chat.additionalReadAccessPaths', ConfigType.Simple, []);
 	export const SwitchAgentEnabled = defineSetting<boolean>('chat.switchAgent.enabled', ConfigType.ExperimentBased, false);
+	export const SwitchAgentConfirm = defineSetting<boolean>('chat.switchAgent.confirm', ConfigType.Simple, true);
 
 	/** Additional tools to enable for the Plan agent (additive to base tools) */
 	export const PlanAgentAdditionalTools = defineSetting<string[]>('chat.planAgent.additionalTools', ConfigType.Simple, []);