Counting agents have a number of important roles to play at the count:
they observe the counting process and make sure that it is accurate
they can draw to the attention of count staff any doubtful ballot papers
if they disagree with a decision by the (Acting) Returning Officer ((A)RO) to reject a ballot paper, they can ask the (A)RO to mark on the ballot paper “rejection objected to”
if a count is suspended for any reason, counting agents can add their seals when the (Acting) Returning Officer seals the ballot boxes and envelopes
You and your election agent can do anything a counting agent is allowed to do.