### Check for existing issues

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

### The Feature

Ability to attach user-specific metadata to each tool call For tool call types' mcp_call and function_call, I request the ability to add metadata to user-specific requirements for .e.g - Attaching external tool_id, user_id's, session_id(user's side) to the tool calls

### Motivation, pitch

Motivation is simple to make litellm more versatile for enterprise use cases

### What part of LiteLLM is this about?

SDK (litellm Python package)

### LiteLLM is hiring a founding backend engineer, are you interested in joining us and shipping to all our users?

Yes

### Twitter / LinkedIn details

_No response_