client overrides for tool argument descriptions

### StatGPT Backend version

latest

### What is the problem this feature will solve?

currently it's no possible to:

1. override a tool argument description in the client config
2. see the current tool argument descriptions in admin module

### What is the proposed feature or solution?

- save tool arg descriptions in the config
- expose them in tool config to be able to see from statgpt admin

### What alternatives have you considered?

_No response_

Start by tracing the client configuration and the tool configuration exposed by the admin module. Implement support for saving client-level tool argument descriptions and exposing the current descriptions in the tool configuration; done means both requested views reflect configured overrides.

Written by the indexing model from the issue text.