The real cost of running an AI agent is the people watching it
McKinsey's practitioner guide to agent economics finds token costs are typically just 20 to 25% of an AI agent's variable running costs, while human oversight accounts for 70 to 75%. A single-agent banking service workflow costs $20,000 to $30,000 to run; a conversational onboarding agent for 2,500 customers a year costs $10,000 to $15,000.
Why it matters
Process design, not model procurement, is the lever on agent cost. What matters is what proportion of runs get reviewed and by whom: McKinsey's own onboarding example puts 10 to 20% of runs in front of a risk or functional expert.