fix(read_multple_files): add missing items property

Author: jochil

filesystemserver/server.go

@@ -127,6 +127,7 @@ func NewFilesystemServer(allowedDirs []string) (*server.MCPServer, error) {
 		mcp.WithArray("paths",
 			mcp.Description("List of file paths to read"),
 			mcp.Required(),
+			mcp.Items(map[string]any{"type": "string"}),
 		),
 	), h.handleReadMultipleFiles)
 

filesystemserver/server_test.go

@@ -0,0 +1,28 @@
+package filesystemserver_test
+
+import (
+	"testing"
+
+	"github.com/mark3labs/mcp-filesystem-server/filesystemserver"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// regression test for invalid schema => missing items in array definition
+func TestReadMultipleFilesSchema(t *testing.T) {
+	fsserver, err := filesystemserver.NewFilesystemServer([]string{t.TempDir()})
+	require.NoError(t, err)
+
+	mcpClient := startTestClient(t, fsserver)
+
+	tool := getTool(t, mcpClient, "read_multiple_files")
+	require.NotNil(t, tool)
+
+	// make sure that the tool has the correct schema
+	paths, ok := tool.InputSchema.Properties["paths"]
+	assert.True(t, ok)
+	pathsMap, ok := paths.(map[string]any)
+	assert.True(t, ok)
+	_, ok = pathsMap["items"]
+	assert.True(t, ok)
+}