Assistant: Initial pass at implementing a data summary tool for Python

extensions/positron-assistant/package.json

@@ -336,6 +336,39 @@
           "positron-assistant"
         ]
       },
+      {
+        "name": "getTableSummary",
+        "displayName": "Get Table Summary",
+        "modelDescription": "Get structured information about table variables in the current session.",
+        "inputSchema": {
+          "type": "object",
+          "properties": {
+            "sessionIdentifier": {
+              "type": "string",
+              "description": "The identifier of the session that contains the tables."
+            },
+            "accessKeys": {
+              "type": "array",
+              "description": "An array of table variables to summarize.",
+              "items": {
+                "type": "array",
+                "description": "A list of access keys that identify a variable by specifying its path.",
+                "items": {
+                  "type": "string",
+                  "description": "An access key that uniquely identifies a variable among its siblings."
+                }
+              }
+            }
+          },
+          "required": [
+            "sessionIdentifier",
+            "accessKeys"
+          ]
+        },
+        "tags": [
+          "positron-assistant"
+        ]
+      },
       {
         "name": "getProjectTree",
         "displayName": "Get Project Tree",

extensions/positron-assistant/src/md/prompts/chat/agent.md

@@ -23,6 +23,23 @@ results, generate the code and return it directly without trying to execute it.
 <package-management>
 You adhere to the following workflow when dealing with package management:
 
+**Data Object Information Workflow:**
+
+When the user asks questions that require detailed information about tabular
+data objects (DataFrames, arrays, matrices, etc.), use the `getTableSummary`
+tool to retrieve structured information such as data summaries and statistics.
+
+To use the tool effectively:
+
+1. First ensure you have the correct `sessionIdentifier` from the user context
+2. Provide the `accessKeys` array with the path to the specific data objects
+   - Each access key is an array of strings representing the path to the variable
+   - If the user references a variable by name, determine the access key from context or previous tool results
+3. Do not call this tool when:
+   - The variables do not appear in the user context
+   - There is no active session
+   - The user only wants to see the structure/children of objects (use `inspectVariables` instead)
+
 **Package Management Workflow:**
 
 1. Before generating code that requires packages, you must first use the appropriate tool to check if each required package is installed. To do so, first determine the target language from the user's request or context

extensions/positron-assistant/src/tools.ts

@@ -299,6 +299,56 @@ export function registerAssistantTools(
 
 	context.subscriptions.push(inspectVariablesTool);
 
+	const getTableSummaryTool = vscode.lm.registerTool<{ sessionIdentifier: string; accessKeys: Array<Array<string>> }>(PositronAssistantToolName.GetTableSummary, {
+		/**
+		 * Called to get a summary information for one or more tabular datasets in the current session.
+		 * @param options The options for the tool invocation.
+		 * @param token The cancellation token.
+		 * @returns A vscode.LanguageModelToolResult containing the data summary.
+		 */
+		invoke: async (options, token) => {
+
+			// If no session identifier is provided, return an empty array.
+			if (!options.input.sessionIdentifier || options.input.sessionIdentifier === 'undefined') {
+				return new vscode.LanguageModelToolResult([
+					new vscode.LanguageModelTextPart('[[]]')
+				]);
+			}
+
+			// temporarily only enable for Python sessions
+			let session: positron.LanguageRuntimeSession | undefined;
+			const sessions = await positron.runtime.getActiveSessions();
+			if (sessions && sessions.length > 0) {
+				session = sessions.find(
+					(session) => session.metadata.sessionId === options.input.sessionIdentifier,
+				);
+			}
+			if (!session) {
+				return new vscode.LanguageModelToolResult([
+					new vscode.LanguageModelTextPart('[[]]')
+				]);
+			}
+
+			if (session.runtimeMetadata.languageId !== 'python') {
+				return new vscode.LanguageModelToolResult([
+					new vscode.LanguageModelTextPart('[[]]')
+				]);
+			}
+
+			// Call the Positron API to get the session variable data summaries
+			const result = await positron.runtime.querySessionTables(
+				options.input.sessionIdentifier,
+				options.input.accessKeys,
+				['summary_stats']);
+
+			// Return the result as a JSON string to the model
+			return new vscode.LanguageModelToolResult([
+				new vscode.LanguageModelTextPart(JSON.stringify(result))
+			]);
+		}
+	});
+	context.subscriptions.push(getTableSummaryTool);
+
 	const installPythonPackageTool = vscode.lm.registerTool<{
 		packages: string[];
 	}>(PositronAssistantToolName.InstallPythonPackage, {

extensions/positron-assistant/src/types.ts

@@ -7,6 +7,7 @@ export enum PositronAssistantToolName {
 	DocumentEdit = 'documentEdit',
 	EditFile = 'positron_editFile_internal',
 	ExecuteCode = 'executeCode',
+	GetTableSummary = 'getTableSummary',
 	GetPlot = 'getPlot',
 	InstallPythonPackage = 'installPythonPackage',
 	InspectVariables = 'inspectVariables',