AI SDK v5 useChat + tools: no messages contain tool parts

  const stream = await agent.stream(messages, {
    memory: {
      resource: user.id,
      thread: threadId,
    },
    format: "aisdk",
    onChunk: (chunk) => {
      console.log("chunk", chunk);
    }
  });
  return stream.toUIMessageStreamResponse();

chunk {
  chunk: {
    type: 'tool-input-start',
    id: 'd8MTApiRjggH0cm5',
    toolName: 'context7_resolve-library-id',
    ...
  }
}
chunk {
  chunk: {
    type: 'tool-input-delta',
    id: 'd8MTApiRjggH0cm5',
    delta: '{"libraryName":"Prisma"}',
    ...
  }
}
chunk {
  chunk: {
    type: 'tool-call',
    toolCallId: 'd8MTApiRjggH0cm5',
    ...
    toolName: 'context7_resolve-library-id',
    input: { libraryName: 'Prisma' }
  }
}
chunk {
  chunk: {
    type: 'tool-result',
    input: { libraryName: 'Prisma' },
    toolCallId: 'd8MTApiRjggH0cm5',
    ...
    toolName: 'context7_resolve-library-id',
    output: { content: [Array] }
  }
}

  const { messages, setMessages, sendMessage, status } = useChat({
    onData: (data) => {
      console.log("data", data); // No logs
    },
    onToolCall: (toolCall) => {
      console.log("toolCall", toolCall); // No logs
    },
    transport: new DefaultChatTransport({
      api: "/api/chat"
    }),
  });