### Check for existing issues

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

### What happened?

### What happened?

`tool_name_to_display_name` and `tool_name_to_description` are ignored when an MCP server is configured through `config.yaml`.

The database/admin UI loading path appears to preserve these fields, but the YAML configuration loader does not pass them into the `MCPServer` object.

### LiteLLM version

Reproduced with:

- v1.91.0 - v1.94.0 - v1.95.0-rc.1 - current `main`

### Configuration

```yaml mcp_servers: example_server: transport: http url: "http://127.0.0.1:8000/mcp" auth_type: none allow_all_keys: true tool_name_to_display_name: example_tool: example_tool ```

The upstream MCP server returns:

```text example_tool ```

LiteLLM returns:

```text example_server-example_tool ```

### Expected behavior

LiteLLM should apply the configured display-name overrides and return:

```text example_tool ```

The reverse mapping should continue routing calls to the original prefixed tools.

### Root cause

In `MCPServerManager.load_servers_from_config()`, the YAML loader constructs `MCPServer(...)` with f…