### Checklist - [x] I'm using the latest version of the extension (Run `glab --version`) - Extension version: 1.80.4 (f4b518e9) - [x] Operating system and version: macOS Darwin 24.6.0 arm64 - [x] Gitlab.com or self-managed instance? self-managed instance - [x] GitLab version (if self-managed): N/A (issue is with MCP server, not GitLab API) - [x] I have performed `glab auth status` to check for authentication issues - [x] Run the command in debug mode and attach any useful output (see logs below) ### Summary When using `glab mcp serve` with MCP clients that prioritize `structuredContent` (like Claude Code), the actual tool output is not displayed. This is because glab's `structuredContent` only contains pagination metadata, not the actual command output. MCP clients like Claude Code prioritize `structuredContent` over `content` for agent performance. Since glab only puts pagination info in `structuredContent`, users see pagination metadata instead of the actual data (e.g., MR list). ### Environment - OS: Darwin 24.6.0 arm64 - SHELL: /bin/zsh - TERM: xterm-256color (via tmux) - GLAB: glab 1.80.4 (f4b518e9) Other: Using Claude Code 2.0.67 as MCP client ### Steps to reproduce 1. Configure `glab mcp serve` as an MCP server in Claude Code (stdio transport) 2. Call any glab tool, e.g., `glab_mr_list` 3. Observe that only pagination metadata is displayed, not the actual MR list ### What is the current _bug_ behavior? glab MCP server returns: ```json { "result": { "content": [ {"type": "text", "text": "Showing 8 open merge requests...\n\n!1359\t..."} ], "structuredContent": { "pagination": { "actual_end": 1006, "actual_size": 1006, "actual_start": 0, "limit": 50000, "offset": 0, "total_size": 1006, "truncated": false } } } } ``` Claude Code (and other MCP clients following the spec) prioritizes `structuredContent`, so users only see: ```json {"pagination":{"actual_end":1006,"actual_size":1006,...}} ``` The actual MR list in `content` is never displayed. ### What is the expected _correct_ behavior? According to the MCP specification and Claude Code's documented behavior (https://github.com/anthropics/claude-code/issues/9962), `structuredContent` should include the actual tool output: **Option 1**: Include actual output in `structuredContent` ```json { "structuredContent": { "output": "Showing 8 open merge requests...", "items": [...], "pagination": {...} } } ``` **Option 2**: Only return `content`, don't return `structuredContent` if it's just metadata ```json { "content": [ {"type": "text", "text": "Showing 8 open merge requests..."} ] } ``` **Option 3**: Add a flag to control behavior ```bash glab mcp serve --no-structured-content ``` ### Relevant logs and/or screenshots MCP server log captured via wrapper script showing the full response: **Request:** ```json {"method":"tools/call","params":{"name":"glab_mr_list","arguments":{}},"jsonrpc":"2.0","id":2} ``` **Response from glab:** ```json {"jsonrpc":"2.0","id":2,"result":{"content":[{"type":"text","text":"Showing 8 open merge requests on synology/OrangeDrive. (Page 1)\n\n!1359\tsynology/OrangeDrive!1359\tfeat: support complex share paths in PathConvertHelper\t(master) ← (WP159)\n!1354\tsynology/OrangeDrive!1354\tfeat: refactor msstore\t(master) ← (appstore)\n..."}],"structuredContent":{"pagination":{"actual_end":1006,"actual_size":1006,"actual_start":0,"limit":50000,"offset":0,"total_size":1006,"truncated":false}}}} ``` **What Claude Code displays:** ```json {"pagination":{"actual_end":1006,"actual_size":1006,"actual_start":0,"limit":50000,"offset":0,"total_size":1006,"truncated":false}} ``` ### Possible fixes **Code location:** [`internal/commands/mcp/serve/server.go:277-286`](https://gitlab.com/gitlab-org/cli/-/blob/main/internal/commands/mcp/serve/server.go#L277-286) ```go return &mcp.CallToolResult{ Content: []mcp.Content{ mcp.TextContent{ Type: "text", Text: processedOutput, }, }, StructuredContent: map[string]any{ "pagination": metadata, // <-- Only pagination, missing actual output }, }, nil ``` **Suggested fix:** Include the actual output in `StructuredContent`: ```go StructuredContent: map[string]any{ "output": processedOutput, // Add actual output here "pagination": metadata, }, ``` Or remove `StructuredContent` entirely if it's only used for pagination metadata. References: - MCP Specification: https://modelcontextprotocol.io/specification/2025-11-25/server/tools - Claude Code issue explaining client behavior: https://github.com/anthropics/claude-code/issues/9962