AI engineering glossary · Agents tools MCP
What is fallback?
Fallback: A backup action used when the primary one fails, such as another tool, a cached answer, a simpler model or a handoff to a human. Planned fallbacks make an agent degrade gracefully instead of failing outright.
Fallback: an example
If the live price API is down, the agent uses yesterday's cached price and tells the user it may be out of date.
Related terms
More Agents tools MCP terms
- Generative agents
- Grounding (agents)
- Guardrails for agents
- Human-in-the-loop
- Human-on-the-loop
- Idempotency (tool calls)
- Indirect prompt injection
- Interrupt (agent)
Where you learn it
Fallback is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.