[BUG] VS Code extension: "Unsupported content type: server_tool_use" and "Unsupported content type: advisor_tool_result" errors displayed in conversation

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Environment

• Claude Code version: 2.1.87
• VS Code extension version: 2.1.87
• OS: macOS Darwin 25.3.0
• Shell: zsh

Description

During conversations that trigger server-side tool calls (specifically the advisor tool), the VS Code extension displays the following errors in the conversation view:

• Unsupported content type: server_tool_use
• Unsupported content type: advisor_tool_result

The tool calls appear to complete successfully on the backend — responses are returned and the conversation continues normally. The errors are display/rendering artifacts in the extension UI.

Additional context

The CLI version and VS Code extension version are in sync (both 2.1.87). The errors do not appear to block functionality — conversations complete successfully.

What Should Happen?

Expected behavior

Unknown or server-side content block types are handled gracefully and not displayed as errors to the user.

Actual behavior

Error messages Unsupported content type: server_tool_use and Unsupported content type: advisor_tool_result are rendered inline in the conversation UI.

Error Messages/Logs

Steps to Reproduce

Steps to reproduce

1. Open a project in VS Code with the Claude Code extension
2. Start a conversation that triggers an advisor tool call (any sufficiently complex coding task)
3. Observe the error messages displayed inline in the conversation

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.87

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_