[plan] Fix unformatted stderr output in MCP CLI files (mcp_config_file, mcp_inspect, mcp_list) #21177

Objective

Replace raw fmt.Fprintf(os.Stderr, ...) calls with console.Format* wrappers across all MCP-related CLI files identified in the Terminal Stylist audit (discussion #21126).

Context

The audit found ~54 files with unformatted stderr output. This issue covers the MCP command group.

Files to Modify

All files are in pkg/cli/:

• mcp_config_file.go
• mcp_inspect.go
• mcp_inspect_inspector.go
• mcp_inspect_list.go
• mcp_inspect_mcp.go
• mcp_list.go

Approach

For each file:

1. Find all fmt.Fprintf(os.Stderr, ...) and fmt.Fprintln(os.Stderr, ...) calls that are NOT already using console formatters
2. Choose the correct formatter based on message semantics:
   • Info/neutral → console.FormatInfoMessage
   • Success/completion → console.FormatSuccessMessage
   • Warning → console.FormatWarningMessage
   • Error → console.FormatErrorMessage
   • Command display → console.FormatCommandMessage
   • List items → console.FormatListItem
3. Convert fmt.Fprintf(os.Stderr, "...\n", args...) → fmt.Fprintln(os.Stderr, console.FormatXxxMessage(fmt.Sprintf("...", args...)))
4. Run make fmt && make test-unit to validate

Note

Do NOT change:

• Calls that already wrap a console.Format* function
• Calls that output structured data (JSON, tables) which go to stdout

Acceptance Criteria

• All raw fmt.Fprintf(os.Stderr, ...) diagnostic messages in the 6 MCP files replaced with console formatters
• make fmt passes with no changes
• make test-unit passes

Generated by Plan Command for issue #discussion #21126 · ◷

• expires on Mar 18, 2026, 5:12 AM UTC