Copilots can often be reviewed one response at a time. Agents require a broader evaluation because they may take several valid paths, call different tools and modify state before producing an answer.
A useful test set should include realistic end-to-end tasks such as: identify all change-of-control clauses for a named entity, link each finding to the executed agreement, route unresolved exceptions to the correct owner and leave the workflow in the expected state. Evaluation should then examine:
- whether the final business outcome is correct;
- whether the agent used only authorized sources and tools;
- whether every material assertion retains evidence;
- whether it stopped or escalated under the defined conditions;
- whether retries created duplicates or contradictory records;
- whether performance remains reliable across repeated runs and difficult edge cases.
This is why tool design matters. Anthropic’s September 2025 guidance on writing effective tools for agents recommends clear functional boundaries, meaningful context and evaluations grounded in realistic multi-step work. The lesson for M&A is direct: a successful demonstration is not proof that an agent can operate safely inside a live deal.
Version every meaningful component—model, instructions, tools, permission policy and evaluation set—so changes can be traced to changes in behavior. Controlled delegation requires a release discipline closer to software and process management than to ordinary prompt writing.