add mcp list-tools to list available tool calls

Author: burmudar

cmd/src/mcp.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+func init() {
+	flagSet := flag.NewFlagSet("mcp", flag.ExitOnError)
+	handler := func(args []string) error {
+		return mcpMain(args)
+	}
+
+	commands = append(commands, &command{
+		flagSet: flagSet,
+		handler: handler,
+	})
+}
+func mcpMain(args []string) error {
+	fmt.Println("NOTE: This command is still experimental")
+	tools, err := LoadMCPToolDefinitions(mcpToolListJSON)
+	if err != nil {
+		return err
+	}
+
+	subcmd := args[0]
+	if subcmd == "list-tools" {
+		fmt.Println("Available tools")
+		for name := range tools {
+			fmt.Printf("- %s\n", name)
+		}
+		return nil
+	}
+
+	tool, ok := tools[subcmd]
+	if !ok {
+		return fmt.Errorf("tool definition for %q not found - run src mcp list-tools to see a list of available tools", subcmd)
+	}
+	return handleMcpTool(tool, args[1:])
+}
+
+func handleMcpTool(tool *MCPToolDef, args []string) error {
+	fmt.Printf("handling tool %q args: %+v", tool.Name, args)
+	return nil
+}

cmd/src/mcp_parse.go

@@ -5,6 +5,7 @@ import (
 	_ "embed"
 	"encoding/json"
 	"fmt"
+	"strings"
 
 	"github.com/sourcegraph/sourcegraph/lib/errors"
 )
@@ -143,6 +144,12 @@ func (p *Parser) parseProperties(props map[string]json.RawMessage) map[string]Sc
 	return res
 }
 
+// normalizeToolName takes mcp tool names like 'sg_keyword_search' and normalizes it to 'keyword-search"
+func normalizeToolName(toolName string) string {
+	toolName, _ = strings.CutPrefix(toolName, "sg_")
+	return strings.ReplaceAll(toolName, "_", "-")
+}
+
 func LoadMCPToolDefinitions(data []byte) (map[string]*MCPToolDef, error) {
 	defs := struct {
 		Tools []struct {
@@ -154,15 +161,15 @@ func LoadMCPToolDefinitions(data []byte) (map[string]*MCPToolDef, error) {
 	}{}
 
 	if err := json.Unmarshal(data, &defs); err != nil {
-		// TODO: think we should panic instead
 		return nil, err
 	}
 
 	tools := map[string]*MCPToolDef{}
 	parser := &Parser{}
 
 	for _, t := range defs.Tools {
-		tools[t.Name] = &MCPToolDef{
+		name := normalizeToolName(t.Name)
+		tools[name] = &MCPToolDef{
 			Name:         t.Name,
 			Description:  t.Description,
 			InputSchema:  parser.parseRootSchema(t.InputSchema),