Bryanmorgan/add mcp description support (#825)

docs/cli/commands.md

@@ -11,6 +11,19 @@ Slash commands provide meta-level control over the CLI itself. They can typicall
   - **Description:** Displays help information about the Gemini CLI, including available commands and their usage.
   - **Action:** Opens a help dialog or section within the CLI.
 
+- **`/mcp`** (Toggle descriptions: **Ctrl+T**)
+
+  - **Description:** Lists configured Model Context Protocol (MCP) servers and their available tools.
+  - **Action:** Displays a formatted list of MCP servers with connection status indicators, server details, and available tools.
+  - **Sub-commands:**
+    - **`desc`** or **`descriptions`**:
+      - **Description:** Shows detailed descriptions for MCP servers and tools.
+      - **Action:** Displays each tool's name with its full description, formatted for readability.
+    - **`nodesc`** or **`nodescriptions`**:
+      - **Description:** Hides tool descriptions, showing only the tool names.
+      - **Action:** Displays a compact list with only tool names.
+  - **Keyboard Shortcut:** Press **Ctrl+T** at any time to toggle between showing and hiding tool descriptions.
+
 - **`/clear`** (Shortcut: **Ctrl+L**)
 
   - **Description:** Clears the entire terminal screen, including the visible session history and scrollback within the CLI.

packages/cli/src/ui/App.tsx

@@ -79,6 +79,8 @@ export const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
   const [corgiMode, setCorgiMode] = useState(false);
   const [shellModeActive, setShellModeActive] = useState(false);
   const [showErrorDetails, setShowErrorDetails] = useState<boolean>(false);
+  const [showToolDescriptions, setShowToolDescriptions] =
+    useState<boolean>(false);
   const [ctrlCPressedOnce, setCtrlCPressedOnce] = useState(false);
   const ctrlCTimerRef = useRef<NodeJS.Timeout | null>(null);
 
@@ -87,44 +89,6 @@ export const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     [consoleMessages],
   );
 
-  useInput((input: string, key: InkKeyType) => {
-    if (key.ctrl && input === 'o') {
-      setShowErrorDetails((prev) => !prev);
-      refreshStatic();
-    } else if (key.ctrl && (input === 'c' || input === 'C')) {
-      if (ctrlCPressedOnce) {
-        if (ctrlCTimerRef.current) {
-          clearTimeout(ctrlCTimerRef.current);
-        }
-        process.exit(0);
-      } else {
-        setCtrlCPressedOnce(true);
-        ctrlCTimerRef.current = setTimeout(() => {
-          setCtrlCPressedOnce(false);
-          ctrlCTimerRef.current = null;
-        }, CTRL_C_PROMPT_DURATION_MS);
-      }
-    }
-  });
-
-  useEffect(
-    () => () => {
-      if (ctrlCTimerRef.current) {
-        clearTimeout(ctrlCTimerRef.current);
-      }
-    },
-    [],
-  );
-
-  useConsolePatcher({
-    onNewMessage: handleNewMessage,
-    debugMode: config.getDebugMode(),
-  });
-
-  const toggleCorgiMode = useCallback(() => {
-    setCorgiMode((prev) => !prev);
-  }, []);
-
   const {
     isThemeDialogOpen,
     openThemeDialog,
@@ -132,11 +96,9 @@ export const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     handleThemeHighlight,
   } = useThemeCommand(settings, setThemeError, addItem);
 
-  useEffect(() => {
+  const toggleCorgiMode = useCallback(() => {
-    if (config) {
+    setCorgiMode((prev) => !prev);
-      setGeminiMdFileCount(config.getGeminiMdFileCount());
+  }, []);
-    }
-  }, [config]);
 
   const performMemoryRefresh = useCallback(async () => {
     addItem(
@@ -190,8 +152,61 @@ export const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
     openThemeDialog,
     performMemoryRefresh,
     toggleCorgiMode,
+    showToolDescriptions,
   );
 
+  useInput((input: string, key: InkKeyType) => {
+    if (key.ctrl && input === 'o') {
+      setShowErrorDetails((prev) => !prev);
+      refreshStatic();
+    } else if (key.ctrl && input === 't') {
+      // Toggle showing tool descriptions
+      const newValue = !showToolDescriptions;
+      setShowToolDescriptions(newValue);
+      refreshStatic();
+
+      // Re-execute the MCP command to show/hide descriptions
+      const mcpServers = config.getMcpServers();
+      if (Object.keys(mcpServers || {}).length > 0) {
+        // Pass description flag based on the new value
+        handleSlashCommand(newValue ? '/mcp desc' : '/mcp nodesc');
+      }
+    } else if (key.ctrl && (input === 'c' || input === 'C')) {
+      if (ctrlCPressedOnce) {
+        if (ctrlCTimerRef.current) {
+          clearTimeout(ctrlCTimerRef.current);
+        }
+        process.exit(0);
+      } else {
+        setCtrlCPressedOnce(true);
+        ctrlCTimerRef.current = setTimeout(() => {
+          setCtrlCPressedOnce(false);
+          ctrlCTimerRef.current = null;
+        }, CTRL_C_PROMPT_DURATION_MS);
+      }
+    }
+  });
+
+  useEffect(
+    () => () => {
+      if (ctrlCTimerRef.current) {
+        clearTimeout(ctrlCTimerRef.current);
+      }
+    },
+    [],
+  );
+
+  useConsolePatcher({
+    onNewMessage: handleNewMessage,
+    debugMode: config.getDebugMode(),
+  });
+
+  useEffect(() => {
+    if (config) {
+      setGeminiMdFileCount(config.getGeminiMdFileCount());
+    }
+  }, [config]);
+
   const { streamingState, submitQuery, initError, pendingHistoryItems } =
     useGeminiStream(
       config.getGeminiClient(),
@@ -422,6 +437,7 @@ export const App = ({ config, settings, startupWarnings = [] }: AppProps) => {
                         getCurrentGeminiMdFilename()
                       }
                       mcpServers={config.getMcpServers()}
+                      showToolDescriptions={showToolDescriptions}
                     />
                   )}
                 </Box>

packages/cli/src/ui/components/ContextSummaryDisplay.tsx

@@ -13,12 +13,14 @@ interface ContextSummaryDisplayProps {
   geminiMdFileCount: number;
   contextFileName: string;
   mcpServers?: Record<string, MCPServerConfig>;
+  showToolDescriptions?: boolean;
 }
 
 export const ContextSummaryDisplay: React.FC<ContextSummaryDisplayProps> = ({
   geminiMdFileCount,
   contextFileName,
   mcpServers,
+  showToolDescriptions,
 }) => {
   const mcpServerCount = Object.keys(mcpServers || {}).length;
 
@@ -45,6 +47,14 @@ export const ContextSummaryDisplay: React.FC<ContextSummaryDisplayProps> = ({
   }
   if (mcpText) {
     summaryText += mcpText;
+    // Add Ctrl+T hint when MCP servers are available
+    if (mcpServers && Object.keys(mcpServers).length > 0) {
+      if (showToolDescriptions) {
+        summaryText += ' (Ctrl+T to hide descriptions)';
+      } else {
+        summaryText += ' (Ctrl+T to view descriptions)';
+      }
+    }
   }
 
   return <Text color={Colors.Gray}>{summaryText}</Text>;

packages/cli/src/ui/hooks/slashCommandProcessor.test.ts

@@ -49,7 +49,7 @@ vi.mock('node:fs/promises', () => ({
 }));
 
 import { act, renderHook } from '@testing-library/react';
-import { vi, describe, it, expect, beforeEach, Mock } from 'vitest';
+import { vi, describe, it, expect, beforeEach, afterEach, Mock } from 'vitest';
 import open from 'open';
 import {
   useSlashCommandProcessor,
@@ -107,7 +107,7 @@ describe('useSlashCommandProcessor', () => {
     process.env = { ...globalThis.process.env };
   });
 
-  const getProcessor = () => {
+  const getProcessor = (showToolDescriptions: boolean = false) => {
     const { result } = renderHook(() =>
       useSlashCommandProcessor(
         mockConfig,
@@ -119,6 +119,7 @@ describe('useSlashCommandProcessor', () => {
         mockOpenThemeDialog,
         mockPerformMemoryRefresh,
         mockCorgiMode,
+        showToolDescriptions,
       ),
     );
     return result.current;
@@ -571,17 +572,82 @@ Add any other context about the problem here.
       // Check that the message contains details about both servers and their tools
       const message = mockAddItem.mock.calls[1][0].text;
       // Server 1 - Connected (green dot)
-      expect(message).toContain('🟢 server1 (2 tools):');
+      expect(message).toContain('🟢 \u001b[1mserver1\u001b[0m (2 tools)');
-      expect(message).toContain('server1_tool1');
+      expect(message).toContain('\u001b[36mserver1_tool1\u001b[0m');
-      expect(message).toContain('server1_tool2');
+      expect(message).toContain('\u001b[36mserver1_tool2\u001b[0m');
 
       // Server 2 - Connecting (yellow dot)
-      expect(message).toContain('🟡 server2 (1 tools):');
+      expect(message).toContain('🟡 \u001b[1mserver2\u001b[0m (1 tools)');
-      expect(message).toContain('server2_tool1');
+      expect(message).toContain('\u001b[36mserver2_tool1\u001b[0m');
 
       // Server 3 - No status, should default to Disconnected (red dot)
-      expect(message).toContain('🔴 server3 (1 tools):');
+      expect(message).toContain('🔴 \u001b[1mserver3\u001b[0m (1 tools)');
-      expect(message).toContain('server3_tool1');
+      expect(message).toContain('\u001b[36mserver3_tool1\u001b[0m');
+
+      expect(commandResult).toBe(true);
+    });
+
+    it('should display tool descriptions when showToolDescriptions is true', async () => {
+      // Mock MCP servers configuration with server description
+      const mockMcpServers = {
+        server1: {
+          command: 'cmd1',
+          description: 'This is a server description',
+        },
+      };
+
+      // Setup getMCPServerStatus mock implementation
+      vi.mocked(getMCPServerStatus).mockImplementation((serverName) => {
+        if (serverName === 'server1') return MCPServerStatus.CONNECTED;
+        return MCPServerStatus.DISCONNECTED;
+      });
+
+      // Mock tools from server with descriptions
+      const mockServerTools = [
+        { name: 'tool1', description: 'This is tool 1 description' },
+        { name: 'tool2', description: 'This is tool 2 description' },
+      ];
+
+      mockConfig = {
+        ...mockConfig,
+        getToolRegistry: vi.fn().mockResolvedValue({
+          getToolsByServer: vi.fn().mockReturnValue(mockServerTools),
+        }),
+        getMcpServers: vi.fn().mockReturnValue(mockMcpServers),
+      } as unknown as Config;
+
+      const { handleSlashCommand } = getProcessor(true);
+      let commandResult: SlashCommandActionReturn | boolean = false;
+      await act(async () => {
+        commandResult = handleSlashCommand('/mcp');
+      });
+
+      expect(mockAddItem).toHaveBeenNthCalledWith(
+        2,
+        expect.objectContaining({
+          type: MessageType.INFO,
+          text: expect.stringContaining('Configured MCP servers and tools:'),
+        }),
+        expect.any(Number),
+      );
+
+      const message = mockAddItem.mock.calls[1][0].text;
+
+      // Check that server description is included (with ANSI color codes)
+      expect(message).toContain('\u001b[1mserver1\u001b[0m (2 tools)');
+      expect(message).toContain(
+        '\u001b[32mThis is a server description\u001b[0m',
+      );
+
+      // Check that tool descriptions are included (with ANSI color codes)
+      expect(message).toContain('\u001b[36mtool1\u001b[0m');
+      expect(message).toContain(
+        '\u001b[32mThis is tool 1 description\u001b[0m',
+      );
+      expect(message).toContain('\u001b[36mtool2\u001b[0m');
+      expect(message).toContain(
+        '\u001b[32mThis is tool 2 description\u001b[0m',
+      );
 
       expect(commandResult).toBe(true);
     });
@@ -636,9 +702,9 @@ Add any other context about the problem here.
 
       // Check that the message contains details about both servers and their tools
       const message = mockAddItem.mock.calls[1][0].text;
-      expect(message).toContain('🟢 server1 (1 tools):');
+      expect(message).toContain('🟢 \u001b[1mserver1\u001b[0m (1 tools)');
-      expect(message).toContain('server1_tool1');
+      expect(message).toContain('\u001b[36mserver1_tool1\u001b[0m');
-      expect(message).toContain('🔴 server2 (0 tools):');
+      expect(message).toContain('🔴 \u001b[1mserver2\u001b[0m (0 tools)');
       expect(message).toContain('No tools available');
 
       expect(commandResult).toBe(true);

packages/cli/src/ui/hooks/slashCommandProcessor.ts

@@ -47,6 +47,7 @@ export const useSlashCommandProcessor = (
   openThemeDialog: () => void,
   performMemoryRefresh: () => Promise<void>,
   toggleCorgiMode: () => void,
+  showToolDescriptions: boolean = false,
 ) => {
   const addMessage = useCallback(
     (message: Message) => {
@@ -141,6 +142,21 @@ export const useSlashCommandProcessor = (
         name: 'mcp',
         description: 'list configured MCP servers and tools',
         action: async (_mainCommand, _subCommand, _args) => {
+          // Check if the _subCommand includes a specific flag to control description visibility
+          let useShowDescriptions = showToolDescriptions;
+          if (_subCommand === 'desc' || _subCommand === 'descriptions') {
+            useShowDescriptions = true;
+          } else if (
+            _subCommand === 'nodesc' ||
+            _subCommand === 'nodescriptions'
+          ) {
+            useShowDescriptions = false;
+          } else if (_args === 'desc' || _args === 'descriptions') {
+            useShowDescriptions = true;
+          } else if (_args === 'nodesc' || _args === 'nodescriptions') {
+            useShowDescriptions = false;
+          }
+
           const toolRegistry = await config?.getToolRegistry();
           if (!toolRegistry) {
             addMessage({
@@ -184,10 +200,68 @@ export const useSlashCommandProcessor = (
                 break;
             }
 
-            message += `${statusDot} ${serverName} (${serverTools.length} tools):\n`;
+            // Get server description if available
+            const server = mcpServers[serverName];
+
+            // Format server header with bold formatting
+            message += `${statusDot} \u001b[1m${serverName}\u001b[0m (${serverTools.length} tools)`;
+
+            // Add server description with proper handling of multi-line descriptions
+            if (useShowDescriptions && server?.description) {
+              const greenColor = '\u001b[32m';
+              const resetColor = '\u001b[0m';
+
+              const descLines = server.description.split('\n');
+              message += `: ${greenColor}${descLines[0]}${resetColor}`;
+              message += '\n';
+
+              // If there are multiple lines, add proper indentation for each line
+              if (descLines.length > 1) {
+                for (let i = 1; i < descLines.length; i++) {
+                  // Skip empty lines at the end
+                  if (i === descLines.length - 1 && descLines[i].trim() === '')
+                    continue;
+                  message += `    ${greenColor}${descLines[i]}${resetColor}\n`;
+                }
+              }
+            } else {
+              message += '\n';
+            }
+
+            // Reset formatting after server entry
+            message += '\u001b[0m';
+
             if (serverTools.length > 0) {
               serverTools.forEach((tool) => {
-                message += `  - ${tool.name}\n`;
+                if (useShowDescriptions && tool.description) {
+                  // Format tool name in cyan using simple ANSI cyan color
+                  message += `  - \u001b[36m${tool.name}\u001b[0m: `;
+
+                  // Apply green color to the description text
+                  const greenColor = '\u001b[32m';
+                  const resetColor = '\u001b[0m';
+
+                  // Handle multi-line descriptions by properly indenting and preserving formatting
+                  const descLines = tool.description.split('\n');
+                  message += `${greenColor}${descLines[0]}${resetColor}\n`;
+
+                  // If there are multiple lines, add proper indentation for each line
+                  if (descLines.length > 1) {
+                    for (let i = 1; i < descLines.length; i++) {
+                      // Skip empty lines at the end
+                      if (
+                        i === descLines.length - 1 &&
+                        descLines[i].trim() === ''
+                      )
+                        continue;
+                      message += `      ${greenColor}${descLines[i]}${resetColor}\n`;
+                    }
+                  }
+                  // Reset is handled inline with each line now
+                } else {
+                  // Use cyan color for the tool name even when not showing descriptions
+                  message += `  - \u001b[36m${tool.name}\u001b[0m\n`;
+                }
               });
             } else {
               message += '  No tools available\n';
@@ -195,6 +269,9 @@ export const useSlashCommandProcessor = (
             message += '\n';
           }
 
+          // Make sure to reset any ANSI formatting at the end to prevent it from affecting the terminal
+          message += '\u001b[0m';
+
           addMessage({
             type: MessageType.INFO,
             content: message,
@@ -369,6 +446,7 @@ Add any other context about the problem here.
       addMessage,
       toggleCorgiMode,
       config,
+      showToolDescriptions,
     ],
   );
 

packages/core/src/config/config.ts

@@ -49,6 +49,8 @@ export class MCPServerConfig {
     // Common
     readonly timeout?: number,
     readonly trust?: boolean,
+    // Metadata
+    readonly description?: string,
   ) {}
 }
 

packages/core/src/tools/mcp-tool.test.ts

@@ -52,7 +52,7 @@ describe('DiscoveredMCPTool', () => {
   });
 
   describe('constructor', () => {
-    it('should set properties correctly and augment description (non-generic server)', () => {
+    it('should set properties correctly (non-generic server)', () => {
       const tool = new DiscoveredMCPTool(
         mockCallableToolInstance,
         serverName, // serverName is 'mock-mcp-server', not 'mcp'
@@ -64,14 +64,13 @@ describe('DiscoveredMCPTool', () => {
 
       expect(tool.name).toBe(toolNameForModel);
       expect(tool.schema.name).toBe(toolNameForModel);
-      const expectedDescription = `${baseDescription}\n\nThis MCP tool named '${serverToolName}' was discovered from an MCP server.`;
+      expect(tool.schema.description).toBe(baseDescription);
-      expect(tool.schema.description).toBe(expectedDescription);
       expect(tool.schema.parameters).toEqual(inputSchema);
       expect(tool.serverToolName).toBe(serverToolName);
       expect(tool.timeout).toBeUndefined();
     });
 
-    it('should set properties correctly and augment description (generic "mcp" server)', () => {
+    it('should set properties correctly (generic "mcp" server)', () => {
       const genericServerName = 'mcp';
       const tool = new DiscoveredMCPTool(
         mockCallableToolInstance,
@@ -81,8 +80,7 @@ describe('DiscoveredMCPTool', () => {
         inputSchema,
         serverToolName,
       );
-      const expectedDescription = `${baseDescription}\n\nThis MCP tool named '${serverToolName}' was discovered from '${genericServerName}' MCP server.`;
+      expect(tool.schema.description).toBe(baseDescription);
-      expect(tool.schema.description).toBe(expectedDescription);
     });
 
     it('should accept and store a custom timeout', () => {

packages/core/src/tools/mcp-tool.ts

@@ -30,17 +30,6 @@ export class DiscoveredMCPTool extends BaseTool<ToolParams, ToolResult> {
     readonly timeout?: number,
     readonly trust?: boolean,
   ) {
-    if (serverName !== 'mcp') {
-      // Add server name if not the generic 'mcp'
-      description += `
-
-This MCP tool named '${serverToolName}' was discovered from an MCP server.`;
-    } else {
-      description += `
-
-This MCP tool named '${serverToolName}' was discovered from '${serverName}' MCP server.`;
-    }
-
     super(
       name,
       name,