Implement tiger mcp list command (#120)

Author: nathanjcochran

CLAUDE.md

@@ -270,7 +270,7 @@ Tiger CLI is a Go-based command-line interface for managing Tiger, the modern da
   - `service.go` - Service management commands (list, create, get, fork, start, stop, delete, update-password)
   - `db.go` - Database operation commands (connection-string, connect, test-connection)
   - `config.go` - Configuration management commands (show, set, unset, reset)
-  - `mcp.go` - MCP server commands (install, start)
+  - `mcp.go` - MCP server commands (install, start, list)
   - `version.go` - Version command
 - **Configuration**: `internal/tiger/config/config.go` - Centralized config with Viper integration
 - **Logging**: `internal/tiger/logging/logging.go` - Structured logging with zap
@@ -280,6 +280,7 @@ Tiger CLI is a Go-based command-line interface for managing Tiger, the modern da
   - `service_tools.go` - Service management tools (list, get, create, fork, start, stop, update-password)
   - `db_tools.go` - Database operation tools (execute-query)
   - `proxy.go` - Proxy client that forwards tools/resources/prompts from remote docs MCP server
+  - `capabilities.go` - Lists all available MCP capabilities (tools, prompts, resources, resource templates)
 - **Common Package**: `internal/tiger/common/` - Shared business logic used by both CLI and MCP
   - Password storage utilities (keyring, pgpass, validation)
   - Wait operations and polling logic (WaitForService)

README.md

@@ -104,6 +104,7 @@ Tiger CLI provides the following commands:
 - `tiger mcp` - MCP server setup and management
   - `install` - Install and configure MCP server for an AI assistant
   - `start` - Start the MCP server
+  - `list` - List available MCP tools, prompts, and resources
 - `tiger version` - Show version information
 
 Use `tiger <command> --help` for detailed information about each command.
@@ -182,8 +183,8 @@ The MCP server automatically uses your CLI authentication and configuration, so
 
 In addition to the service management tools listed above, the Tiger MCP server also proxies tools from a remote documentation MCP server. This feature provides AI assistants with semantic search capabilities for PostgreSQL, TimescaleDB, and Tiger Cloud documentation, as well as prompts/guides for various Tiger Cloud features.
 
-The proxied documentation server ([tiger-docs-mcp-server](https://github.com/timescale/tiger-docs-mcp-server)) currently provides the following tools:
-- `get_guide` - Retrieve comprehensive guides for TimescaleDB features and best practices
+The proxied documentation server ([pg-aiguide](https://github.com/timescale/pg-aiguide)) currently provides the following tools:
+- `view_skill` - Retrieve comprehensive guides for TimescaleDB features and best practices
 - `semantic_search_postgres_docs` - Search PostgreSQL documentation using natural language queries
 - `semantic_search_tiger_docs` - Search Tiger Cloud and TimescaleDB documentation using natural language queries
 

internal/tiger/cmd/mcp.go

@@ -4,14 +4,18 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"net"
 	"net/http"
 
+	"github.com/olekukonko/tablewriter"
 	"github.com/spf13/cobra"
 	"go.uber.org/zap"
 
+	"github.com/timescale/tiger-cli/internal/tiger/config"
 	"github.com/timescale/tiger-cli/internal/tiger/logging"
 	"github.com/timescale/tiger-cli/internal/tiger/mcp"
+	"github.com/timescale/tiger-cli/internal/tiger/util"
 )
 
 // buildMCPCmd creates the MCP server command with subcommands
@@ -40,6 +44,7 @@ Use 'tiger mcp start' to launch the MCP server.`,
 	// Add subcommands
 	cmd.AddCommand(buildMCPInstallCmd())
 	cmd.AddCommand(buildMCPStartCmd())
+	cmd.AddCommand(buildMCPListCmd())
 
 	return cmd
 }
@@ -91,7 +96,7 @@ Examples:
 			if len(args) == 0 {
 				// No client specified, prompt user to select one
 				var err error
-				clientName, err = selectClientInteractively(cmd.OutOrStdout())
+				clientName, err = selectClientInteractively(cmd.ErrOrStderr())
 				if err != nil {
 					return fmt.Errorf("failed to select client: %w", err)
 				}
@@ -206,6 +211,74 @@ Examples:
 	return cmd
 }
 
+// buildMCPListCmd creates the list subcommand for displaying available MCP capabilities
+func buildMCPListCmd() *cobra.Command {
+	var outputFormat string
+
+	cmd := &cobra.Command{
+		Use:   "list",
+		Short: "List available MCP tools, prompts, and resources",
+		Long: `List all MCP tools, prompts, and resources exposed via the Tiger MCP server.
+
+The output can be formatted as a table, JSON, or YAML.
+
+Examples:
+  # List all capabilities in table format (default)
+  tiger mcp list
+
+  # List as JSON
+  tiger mcp list -o json
+
+  # List as YAML
+  tiger mcp list -o yaml`,
+		Args:              cobra.NoArgs,
+		ValidArgsFunction: cobra.NoFileCompletions,
+		PreRunE:           bindFlags("output"),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cmd.SilenceUsage = true
+
+			// Get config
+			cfg, err := config.Load()
+			if err != nil {
+				return fmt.Errorf("failed to load config: %w", err)
+			}
+
+			// Create MCP server
+			server, err := mcp.NewServer(cmd.Context())
+			if err != nil {
+				return fmt.Errorf("failed to create MCP server: %w", err)
+			}
+			defer server.Close()
+
+			// List capabilities
+			capabilities, err := server.ListCapabilities(cmd.Context())
+			if err != nil {
+				return fmt.Errorf("failed to list capabilities: %w", err)
+			}
+
+			// Close the MCP server when finished
+			if err := server.Close(); err != nil {
+				return fmt.Errorf("failed to close MCP server: %w", err)
+			}
+
+			// Format output
+			output := cmd.OutOrStdout()
+			switch cfg.Output {
+			case "json":
+				return util.SerializeToJSON(output, capabilities)
+			case "yaml":
+				return util.SerializeToYAML(output, capabilities, true)
+			default:
+				return outputCapabilitiesTable(output, capabilities)
+			}
+		},
+	}
+
+	cmd.Flags().VarP((*outputFlag)(&outputFormat), "output", "o", "output format (json, yaml, table)")
+
+	return cmd
+}
+
 // startStdioServer starts the MCP server with stdio transport
 func startStdioServer(ctx context.Context) error {
 	logging.Info("Starting Tiger MCP server", zap.String("transport", "stdio"))
@@ -215,10 +288,10 @@ func startStdioServer(ctx context.Context) error {
 	if err != nil {
 		return fmt.Errorf("failed to create MCP server: %w", err)
 	}
+	defer server.Close()
 
 	// Start the stdio transport
-	err = server.StartStdio(ctx)
-	if err != nil && !errors.Is(err, context.Canceled) {
+	if err := server.StartStdio(ctx); err != nil && !errors.Is(err, context.Canceled) {
 		return fmt.Errorf("failed to start MCP server: %w", err)
 	}
 
@@ -238,6 +311,7 @@ func startHTTPServer(ctx context.Context, host string, port int) error {
 	if err != nil {
 		return fmt.Errorf("failed to create MCP server: %w", err)
 	}
+	defer server.Close()
 
 	// Find available port and get the listener
 	listener, actualPort, err := getListener(host, port)
@@ -302,3 +376,32 @@ func getListener(host string, startPort int) (net.Listener, int, error) {
 	}
 	return nil, 0, fmt.Errorf("no available port found in range %d-%d", startPort, startPort+99)
 }
+
+// outputCapabilitiesTable outputs capabilities in table format. Results are
+// ordered alphabetically by type, then name.
+func outputCapabilitiesTable(output io.Writer, capabilities *mcp.Capabilities) error {
+	table := tablewriter.NewWriter(output)
+	table.Header("TYPE", "NAME")
+
+	// Add prompts
+	for _, prompt := range capabilities.Prompts {
+		table.Append("prompt", prompt.Name)
+	}
+
+	// Add resources
+	for _, resource := range capabilities.Resources {
+		table.Append("resource", resource.Name)
+	}
+
+	// Add resource templates
+	for _, template := range capabilities.ResourceTemplates {
+		table.Append("resource_template", template.Name)
+	}
+
+	// Add tools
+	for _, tool := range capabilities.Tools {
+		table.Append("tool", tool.Name)
+	}
+
+	return table.Render()
+}