MCP tool-result widgets render as empty boxes (Claude Code Desktop)

What happens

In Claude Code Desktop, when an MCP tool returns a rich "widget" result, the app renders a labelled but completely empty container instead of the content. Observed with the Atlassian MCP connector: tool results show as blank bordered boxes captioned Widget from Atlassian editJiraIssue and Rendering widget transitionJiraIssue, with no content inside.

The underlying tool call succeeds (the Jira issue is edited / transitioned correctly) — only the UI rendering is blank.

Expected

Render the tool-result content inside the widget, or fall back to the standard collapsible tool-result view. Never an empty box.

Steps to reproduce

1. Connect an MCP server that returns rich widget content (reproduced with the Atlassian connector).
2. Have the agent call a tool such as editJiraIssue or transitionJiraIssue.
3. Observe the result blocks render as empty Widget from … <tool> / Rendering widget <tool> boxes.

Impact

Cosmetic but confusing — a successful tool call looks like it failed or returned nothing. Likely affects any MCP tool returning the rich-widget content type, not just Atlassian.

Environment

• Claude Code Desktop
• macOS 26.5 (build 25F71)
• MCP server: Atlassian connector