## What happened

Sending a request with a server-side tool definition of `type: tool_search_tool_regex_20251119` (Anthropic's [tool-search](https://docs.anthropic.com/en/docs/build-with-claude/tool-use/tool-search) beta, dated SDK version pin) through `bedrock_invoke` fails with:

``` Input tag 'tool_search_tool_regex_20251119' found using 'type' does not match any of the expected tags: 'bash_20241022', 'bash_20250124', 'computer_20241022', 'computer_20250124', 'custom', 'memory_20250818', 'text_editor_20241022', 'text_editor_20250124', 'text_editor_20250429', 'text_editor_20250728', 'web_search_20250305' ```

The matching `anthropic-beta` header is `advanced-tool-use-2025-11-20` (or `tool-search-tool-2025-10-19` on Bedrock/Vertex per `litellm/types/llms/anthropic_tool_search.py`). The header *is* being forwarded, but the Bedrock Invoke request transformer's tool-type allow-list doesn't include `tool_search_tool_regex_20251119`, so the request never reaches Bedrock.

Anthropic-native + Azure + Bedrock Converse + Vertex AI all accept the same payload (return 200).

## Reproducer

```bash curl -s -X POST http://127.0.0.1:4000/v1/messages \ -H "Authorization: Bearer sk-1234" \ -H…