File annotation breaks the link

[abomariam]

GPT-4 returns the links as Markup link [Label](example_url). If you modify this format by entering anything before the closing ), the URL will not be displayed correctly.

Here is the response message from OpenAI APIs

{
  "annotations" : [ {
    "container_id" : "cntr_6974532f1fc081908fe0d2ce44b37d7004739b160af8b41f",
    "end_index" : 126,
    "file_id" : "cfile_6974534d264881918c4226c3de03483c",
    "filename" : "attendee_report_nutcracker_2024_12_07_2pm.csv",
    "start_index" : 63,
    "type" : "container_file_citation"
  } ],
  "text" : "Here is your attendee report in CSV format: [Download the CSV](sandbox:/mnt/data/attendee_report_nutcracker_2024_12_07_2pm.csv)",
  "type" : "output_text",
  "logprobs" : [ ]
}

And here is the equivilant ChatKit message with annotations

{
	"type": "thread.item.done",
	"item": {
		"id": "msg_032763fb84653fcd006924534a6f548190b105c0640d3d908f",
		"thread_id": "db166398-82ea-4695-8877-6a92a9d870c1",
		"created_at": "2025-11-24T12:45:01.298359",
		"type": "assistant_message",
		"content": [
			{
				"annotations": [
					{
						"type": "annotation",
						"source": {
							"title": "attendee_report_nutcracker_2024_12_07_2pm.csv",
							"type": "file",
							"filename": "attendee_report_nutcracker_2024_12_07_2pm.csv"
						},
						"index": 126
					}
				],
				"text": "Here is your attendee report in CSV format: [Download the CSV](sandbox:/mnt/data/attendee_report_nutcracker_2024_12_07_2pm.csv)",
				"type": "output_text"
			}
		]
	}
}

The URL text ends at index 126, but we can't add the annotation before the closing ) at index 127 or it'll break the UI.

Here is how it looks: