### Check for existing issues

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

### What happened?

With `websearch_interception` enabled for Bedrock, a `/v1/messages` request that **forces the web search tool via `tool_choice`** fails with:

``` litellm.llms.base_llm.chat.transformation.BaseLLMException: {"message":"Tool 'web_search' not found in provided tools"} # HTTP 400 from bedrock-runtime .../invoke ```

This is exactly the shape **Claude Code (v2.1.183)** sends for web search — a standalone request with only the web_search tool plus `tool_choice` naming it (captured via a logging proxy) — so web search via Claude Code → LiteLLM → Bedrock is completely broken, while a plain API call without `tool_choice` works.

### Steps to Reproduce

Config: ```yaml model_list: - model_name: bedrock/claude-haiku-4-5 litellm_params: model: bedrock/anthropic.claude-haiku-4-5-20251001-v1:0 # any bedrock claude custom_llm_provider: bedrock litellm_settings: callbacks: ["websearch_interception"] websearch_interception_params: enabled_providers: ["bedrock"] search_tool_name: "my-search" search_tools: - search_tool_name: "m…