chore(tools): centralize pagination cap helper

internal/tools/tool.go

@@ -22,3 +22,14 @@ func parseArgs(raw json.RawMessage, dst any) error {
 }
 
 func _ctx(ctx context.Context) context.Context { return ctx } // stub for future hooks
+
+// capLimit returns a sane page size: 0 or negative → def, > 50 → 50.
+func capLimit(in, def int) int {
+	if in <= 0 {
+		return def
+	}
+	if in > 50 {
+		return 50
+	}
+	return in
+}