### Check for existing issues

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

### What happened?

Received API Error 400 when calling Microsoft Learn MCP server via LiteLLM Proxy v1.83.3 from Claude Code v2.1.114

``` API Error: 400 {"detail":{"error":"{\"message\":\"messages.6.content.0.tool_result.content.0.tool_reference.tool_name: String should have at most 64 characters\"}"}}

```

### Steps to Reproduce

1. claude mcp add --transport http microsoft-learn-mcp $LITELLM_API_BASE/microsoft_learn/mcp --header "x-litellm-api-key: Bearer $LITELLM_API_KEY" 2. claude "Can tell me about.NET 10 File-based App from Microsoft Learn MCP?" 3. A/B testing with/without LLM Proxy to Microsoft Learn MCP 4. Set A: with LiteLLM 50% of time can reproduce above issue 5. Set B: directly go to Microsoft MCP hasn't encountered 400 error

### Relevant log output

```shell API Error: 400 {"detail":{"error":"{\"message\":\"messages.6.content.0.tool_result.content.0.tool_reference.tool_name: String should have at most 64 characters\"}"}} ```

### What part of LiteLLM is this about?

Proxy

### What LiteLLM version are you on ?

v1.83.3

**Li…