Throughout their journey, the Inquisitor has the opportunity to recruit several agents to work for the Inquisition. Many of them can be missed and some might disappear if they are not recruited immediately.
Once they have been recruited, they will work for Cullen, Josephine, or Leliana and will count as perks for the purpose of unlocking other perks within the relevant category (Forces, Secrets, or Connections). They will also reduce the time it takes for the relevant advisor to complete war table missions by five percent.
On some occasions other than the ones listed here, the graphic "Agent Acquired" may show but a new agent will not be added to the perks list. Influence may still be gained in these cases.
Talk to Michel just outside of Sahrnia, then complete Call Me Imshael by defeating Imshael. Return to Michel to recruit him to the Inquisition. Do not make a deal with Imshael, or Michel will be killed.
Speak to Sky Watcher and close the Fade rift next to him before completing Lost Souls. After defeating the Avvar leader, speak to Sky Watcher again to recruit him. Do not leave the Fallow Mire before recruiting Sky Watcher, or he will disappear forever.
Talk to her after completing Praise the Herald of Andraste. Ask that her followers spread the word of the Inquisition to recruit her for Josephine or ask that they listen and gather information to recruit her for Leliana.
After rescuing her during Strange Bedfellows, but before turning in the quest, she can be convinced to join by a dwarf Inquisitor, Varric, or by the Underworld Knowledge perk. It is possible to encounter and recruit Ritts before obtaining the related quest.
If Florianne does not survive, the Inquisitor can judge her remains. Sentencing them to community service makes her an agent.
Note: If Florianne survives and the Inquisitor has the Nobility Knowledge perk, she can be recruited so Josephine can put her guile to use for the Inquisition. However, though the game states "Agent Acquired", Florianne does not appear in the Inquisition perk list and does not affect advisor war table operation completion times.
After Lost Souls, Movran can become an agent if the Inquisitor sentences him and his clan to exile in Tevinter. He can also be conscripted into the Inquisition under the care of Abernache, if the latter survived Champions of the Just.
After speaking with Revered Mother Hevara and the clerics during The Threat Remains, the Inquisitor can speak to the merchant, Belle. She expresses her wish to join the Inquisition and if the Inquisitor accepts her offer she becomes an agent.
Note: Belle will disappear if you speak with Fiona before her.