[BUG] Natural Language Query Fails to generate and run.

[SohaibKatariwala]

What is the bug?
Natural Language Query returns generic failure message and does not produce or run PPL.

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Go to event explorer,
2. select cwl* index pattern. (this index is based on cloudtrail logs from AWS account with lots of activity. 905 fields in index pattern and 10M+ documents.)
3. In natural language query, ask "show me some sample logs."
4. See error

What is the expected behavior?
I expected the query to generate and run some PPL or fail and give a specific error that explain what the issue is (for example: "Too many fields in index, natural language queries are only supported with indexes that have xxx fields or less...")

What is your host/environment?

• OS: Amazon OpenSearch Service; macOS 14.5 (23F79)
• Version OpenSearch_2_13_R20240520-P4
• Plugins; Observability

Do you have any screenshots?
Yes, will add later.

Do you have any additional context?
no

[dblock]

[Catch All Triage - 1, 2, 3]