[feat] Create validator to check text LLM response but to skip tool (function) call.

[whysage]

Description
Please explain if it is currently possible to create validator to check text LLM response (common message in completion.choices[0].message) but to skip tool (function) call (completion.choices[0].message.tool_calls).

Why is this needed
In my case, LLM can pick regular message response or perform a tool call. Only text regular message response must be validated.

Implementation details
It would be great if this check could be inside validator (not like if statement after getting LLM results)

End result
Create many validators only for text response.