nit change

src/participant/participant.ts

@@ -73,7 +73,8 @@ export type RunParticipantCodeCommandArgs = {
   runnableContent: string;
 };
 
-export type ParticipantCommand = '/query' | '/schema' | '/docs';
+export type ParticipantCommandName = 'query' | 'schema' | 'docs';
+export type ParticipantCommand = `/${ParticipantCommandName}`;
 
 const MAX_MARKDOWN_LIST_LENGTH = 10;
 
@@ -179,6 +180,8 @@ export default class ParticipantController {
       message,
       isNewChat = false,
       isPartialQuery = false,
+      source,
+      command,
       ...otherOptions
     } = options;
 
@@ -189,9 +192,26 @@ export default class ParticipantController {
       );
     }
 
+    if (source) {
+      if (isNewChat) {
+        this._telemetryService.trackCopilotParticipantChatOpenedFromAction({
+          source,
+        });
+      }
+      if (!isPartialQuery) {
+        this._telemetryService.trackCopilotParticipantPromptSubmittedFromAction(
+          {
+            source,
+          }
+        );
+      }
+    }
+
+    const commandPrefix = command ? `/${command} ` : '';
+
     return await vscode.commands.executeCommand('workbench.action.chat.open', {
       ...otherOptions,
-      query: `@MongoDB ${message}`,
+      query: `@MongoDB ${commandPrefix}${message}`,
       isPartialQuery,
     });
   }
@@ -207,7 +227,7 @@ export default class ParticipantController {
       ...inputBoxOptions
     } = options;
 
-    this._telemetryService.trackCopilotParticipantSubmittedFromInputBox({
+    this._telemetryService.trackCopilotParticipantPromptSubmittedFromAction({
       source,
     });
 
@@ -236,14 +256,15 @@ export default class ParticipantController {
         message: `I want to ask questions about the \`${databaseName}\` database.`,
         isNewChat: true,
       });
-    }
-    if (treeItem instanceof CollectionTreeItem) {
+    } else if (treeItem instanceof CollectionTreeItem) {
       const { databaseName, collectionName } = treeItem;
 
       await this.sendMessageToParticipant({
         message: `I want to ask questions about the \`${databaseName}\` database's \`${collectionName}\` collection.`,
         isNewChat: true,
       });
+    } else {
+      throw new Error('Unsupported tree item type');
     }
 
     await this.sendMessageToParticipant({
@@ -1949,7 +1970,7 @@ Please see our [FAQ](https://www.mongodb.com/docs/generative-ai-faq/) for more i
     } catch (error) {
       this._telemetryService.trackCopilotParticipantError(
         error,
-        request.command || 'generic'
+        (request.command as ParticipantCommandName) || 'generic'
       );
       // Re-throw other errors so they show up in the UI.
       throw error;