language-server-protocol - Language Server Protocol の Trace 設定の意味は何ですか?

Question

traceLanguage Server Protocolの設定が何をするのかを理解しようとしています。したがって、仕様によると：

初期トレース設定。省略された場合、トレースは無効になります ('off')。

しかし、それは私に多くを教えてくれません。InitializeParamsインターフェイス内に組み込まれています。

interface InitializeParams {
    /**
     * The process Id of the parent process that started
     * the server. Is null if the process has not been started by another process.
     * If the parent process is not alive then the server should exit (see exit notification) its process.
     */
    processId: number | null;

    /**
     * The rootPath of the workspace. Is null
     * if no folder is open.
     *
     * @deprecated in favour of rootUri.
     */
    rootPath?: string | null;

    /**
     * The rootUri of the workspace. Is null if no
     * folder is open. If both `rootPath` and `rootUri` are set
     * `rootUri` wins.
     */
    rootUri: DocumentUri | null;

    /**
     * User provided initialization options.
     */
    initializationOptions?: any;

    /**
     * The capabilities provided by the client (editor or tool)
     */
    capabilities: ClientCapabilities;

    /**
     * The initial trace setting. If omitted trace is disabled ('off').
     */
    trace?: 'off' | 'messages' | 'verbose';

    /**
     * The workspace folders configured in the client when the server starts.
     * This property is only available if the client supports workspace folders.
     * It can be `null` if the client supports workspace folders but none are
     * configured.
     *
     * Since 3.6.0
     */
    workspaceFolders?: WorkspaceFolder[] | null;
}

offテスト言語サーバーでローカルで試してみましたが、( 、messages、 )に値を入れてverboseも、実際には何も変わりません。

それは実際に何をしますか？