diff --git a/webapp/src/components/Params.tsx b/webapp/src/components/Params.tsx
index ff90ec3..248ab2f 100644
--- a/webapp/src/components/Params.tsx
+++ b/webapp/src/components/Params.tsx
@@ -11,6 +11,16 @@ const EMPTY_KIND: ParamDeclaration['kind'] = 'string'
 // sharing the same label set (ticket 038).
 type ExtractionSource = 'regex' | 'json_field' | 'elapsed_since_last'
 
+// The parenthesized suffix shown after a declared-param badge's kind, e.g. "(string, group path)" —
+// one of five possible forms depending on how the param's value is produced.
+function paramBadgeSuffix(p: ParamDeclaration): string {
+  if (p.elapsed_since_last) return ', elapsed since previous'
+  if (p.kind === 'boolean') return ''
+  if (p.json_field_path) return `, json field ${p.json_field_path}`
+  if (p.capture_group !== p.name) return `, group ${p.capture_group}`
+  return ''
+}
+
 /// A JSON *object* (not an array/scalar) parses cleanly and pretty-prints with braces — the same
 /// shape a JSON field path can be read from, so this is the "line looks like JSON" gate that
 /// unlocks the "JSON field" extraction option.
@@ -301,15 +311,7 @@ export function Params({ params, onDeclared }: { params: ParamDeclaration[]; onD
                 title={p.elapsed_since_last ? undefined : p.message_match_regex}
               >
                 {p.name} ({p.kind}
-                {p.elapsed_since_last
-                  ? ', elapsed since previous'
-                  : p.kind === 'boolean'
-                    ? ''
-                    : p.json_field_path
-                      ? `, json field ${p.json_field_path}`
-                      : p.capture_group !== p.name
-                        ? `, group ${p.capture_group}`
-                        : ''}
+                {paramBadgeSuffix(p)}
                 )
               </button>
             ))}