diff --git a/internal/runtime/executor/claude_executor.go b/internal/runtime/executor/claude_executor.go
index 8d8c62c6..c9665385 100644
--- a/internal/runtime/executor/claude_executor.go
+++ b/internal/runtime/executor/claude_executor.go
@@ -45,6 +45,7 @@ func (e *ClaudeExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	}
 	from := opts.SourceFormat
 	to := sdktranslator.FromString("claude")
+	// Use streaming translation to preserve function calling, except for claude.
 	body := sdktranslator.TranslateRequest(from, to, req.Model, bytes.Clone(req.Payload), from != to)
 
 	if !strings.HasPrefix(req.Model, "claude-3-5-haiku") {