Max Input Tokens & Max Output Tokens

Problem/Motivation

Max Input Tokens & Max Output Tokens default to 0, in /admin/config/ai/providers/chat/google_vertex/gemini20flashlite

Often 0 it this kind of config is essentially unlimited.

It would be good to have either better defaults or better errors.

I don't know if this is good:
Max Input Tokens: 1048576
Max Output Tokens: 8192

I kept running into this error:

An error occurred
The following error occurred while processing your request:
Error invoking model response: Unknown Error: Could not get a response from the model.
Of the following exception type:
Drupal\ai\Exception\AiRequestErrorException

Which does make sense, now that I realize that 0=0. It was just hard to debug when working with an unfamiliar system with lots of possible options for what I did wrong.

Steps to reproduce

Install the module from scratch, or set the tokens to:

Max Input Tokens: 0
Max Output Tokens: 0

Proposed resolution

Set some good defaults.

Remaining tasks

User interface changes

API changes

None

Data model changes