The Recon medal is awarded for completing Niantic Wayfarer agreements.
Portal candidates are evaluated by multiple agents, and the final decision to accept or reject the portal is based on the aggregate scoring by those agents. If your evaluation matches the final decision, that constitutes an agreement.
You have an agreement rating based on how frequently you agree with the final decision, which can be “Poor,” “Good,” or “Great.” Agreements you receive while you have a rating of “Good” or “Great” will contribute toward the Recon medal, while those received while your rating is “Poor” will not.
The Recon medal was announced on 12 June 2017.