### Check for existing issues

- [x] I have searched the existing issues and checked that my issue is not a duplicate.

### What happened?

When using Claude Code with Kimi K2P6 via Fireworks AI, tool calls fail because Fireworks rejects JSON Schema properties containing `"default": null` and `"title"` fields inside tool parameter definitions.

`drop_params: true` is already set but has no effect — it only strips **top-level** unsupported API parameters, not nested fields within tool JSON Schemas.

**Error:** ``` litellm.BadRequestError: Fireworks_aiException - {"error":{"object":"error","type":"invalid_request_error","code":"invalid_request_error","message":"JSON Schema not supported: could not understand the instance {'default': None, 'title': 'Page Size'}."}} ```

Fireworks cannot parse tool parameter schemas like: ```json { "properties": { "page_size": { "default": null, "title": "Page Size", "type": "integer" } } } ```

The `default: null` and `title` fields are valid JSON Schema but Fireworks doesn't support them.

### Steps to Reproduce

1. Configure LiteLLM proxy with Fireworks AI provider for Kimi K2P6: ```json { "model_name": "kimi-k2p6",…