fix: add missing debug log in isSingularReadTool

Author: Copilot

internal/server/tool_registry.go

@@ -73,7 +73,9 @@ func getToolResponseFilter(cfg *config.Config, serverID, toolName string) string
 // return a single resource (e.g. get_*, *_read). List/search tools are treated
 // as collection tools even if they happen to return one item.
 func isSingularReadTool(toolName string) bool {
-	return !strings.HasPrefix(toolName, "list_") && !strings.HasPrefix(toolName, "search_")
+	singular := !strings.HasPrefix(toolName, "list_") && !strings.HasPrefix(toolName, "search_")
+	logDifcLog.Printf("isSingularReadTool: toolName=%s, singular=%v", toolName, singular)
+	return singular
 }
 
 // registerAllTools fetches and registers tools from all backend servers