discoverToolsTool function

AgentTool discoverToolsTool({ required Map<String, String> discoverableDocs(), required String onMount(List<String> requested), })

Builds the discover_tools tool.

discoverableDocs — name → one-line doc of the currently discoverable-and-unmounted tools (the gate's live view). onMount — mounts the requested names through the gate and returns the user-facing result text (it reports unknown names itself).

Implementation

AgentTool discoverToolsTool({
  required Map<String, String> Function() discoverableDocs,
  required String Function(List<String> requested) onMount,
}) {
  return AgentTool(
    name: 'discover_tools',
    description:
        'List tools not loaded in this mode, or mount tools by name. '
        'Pass no arguments to list every discoverable tool with a '
        'one-line doc; pass `mount` to load tools into the schema for '
        'the rest of the session.',
    parameters: {
      'type': 'object',
      'properties': {
        'mount': {
          'type': 'array',
          'items': {'type': 'string'},
          'description':
              'Tool NAMES to mount (as listed without arguments). '
              'Omit to only list what is available.',
        },
      },
    },
    execute: (args, cancelToken, onUpdate) async {
      final requested = args['mount'];
      if (requested is! List) {
        final docs = discoverableDocs();
        if (docs.isEmpty) {
          return ToolExecutionResult.text(
            'No discoverable tools — everything available is already '
            'loaded.',
          );
        }
        final listing = [
          for (final entry in docs.entries) '- ${entry.key}: ${entry.value}',
        ].join('\n');
        return ToolExecutionResult.text(
          'Discoverable tools (not loaded; mount with `discover_tools` '
          'mount: [name]):\n$listing',
        );
      }
      final names = [
        for (final item in requested)
          if (item is String && item.trim().isNotEmpty) item.trim(),
      ];
      if (names.isEmpty) {
        return ToolExecutionResult.text(
          'error: mount needs at least one tool name',
        );
      }
      return ToolExecutionResult.text(onMount(names));
    },
  );
}