Here is the full list of all 23 Tales of a Spymaster achievements.
Achieve 100% Trust
Complete the campaign with a faction
Complete the campaign with all factions
Complete the tutorial
Find a traitor in your court
Find a court members secret
Blackmail a court member
Assassinate a court member
Release a poison at a location
Release a plague at a location
Advise attack that captures an enemy capital
Uncover a family secret
Have a revenge fund trigger
Suffer no loses to a volcanic eruption
Investigate every member of court
Earn more than 5000 gold in a given turn
Construct all buildings in a location
Protect a family event from attackers
Succeed in encouraging peace
Succeed in encouraging war
Claim a noble life with your plot
Claim a royal life with your plot
Claim the life of a faction leader with your plot