An assistant mainly helps a person create or understand. An agent can pursue a goal through multiple steps and use permitted tools.
Components of an agentic system
- Goal and instructions.
- Current state and context.
- A loop that chooses the next step.
- Tools with defined input and output schemas.
- Permissions controlling each tool and data source.
- Memory or stored state when the work spans steps or sessions.
- Stop conditions, approvals and recovery.
MCP, the Model Context Protocol, is one way applications expose tools and resources through a common interface. It does not remove the need to trust, permission and monitor the connected server.
Evaluation closes the map
An evaluation, often called an eval, is a repeatable test of the system against examples and a rubric. Evals can measure answer quality, retrieval, safety, latency, cost or tool behaviour.
Without evaluation, teams have impressions. With a representative test set, they can compare versions and see regressions.