Benchmarks reveal both benefits and risks. Successful teams recognize and manage both aspects of the trade-off.
The benefits are tangible. Anthropic's multi-agent research system used one lead agent and several subagents.
It outperformed the best single-agent setup by 90.2% on an internal research test (Anthropic, 2025). Running subagents in parallel also reduced research time by up to 90% on complex queries.
The primary reason is that multi-agent systems allocate more tokens to a problem, distributed across separate context windows. Anthropic found that token usage alone accounted for 80% of the score difference on a challenging benchmark.
However, this increased spending is a significant consideration. According to Anthropic's data, multi-agent systems used about 15 times more tokens than a standard chat. The value of the task must justify the additional cost.
Failure risk is quantifiable. A UC Berkeley team analyzed 1,642 runs across seven multi-agent frameworks.
They found task failure rates ranging from 41% to 86.7% (Cemri et al., 2025). The team categorised 14 failure modes into three groups: design flaws, agents miscommunicating, and insufficient result checking.
Miscommunication between agents is a failure mode unique to multi-agent systems. When tasks are divided, agents may misinterpret each other's output, causing errors to propagate.
The same study demonstrated the effectiveness of mitigation. Adding a single result-checking step increased success on a coding test by 15.6%.
Gartner offers a market warning, predicting that more than 40% of agentic AI projects will be cancelled by the end of 2027.
Key drivers include rising costs, unclear value, and insufficient risk controls (Gartner, 2025). Multi-agent systems are appropriate only when task requirements exceed single-agent capabilities.