AI engineering glossary · Agents tools MCP
What is side effect?
Side effect: A change a tool makes to the outside world beyond returning a value, such as sending a message, writing a file or charging a card. Tools with side effects need extra care, since a wrong call cannot always be undone.
Side effect: an example
A read-only search tool has no side effect; a delete_file tool does, so it is placed behind an approval step.
Related terms
More Agents tools MCP terms
- Skill library
- State graph
- stdio transport
- Stop condition
- Streamable HTTP
- Subagent
- Supervisor agent
- Task success rate
Where you learn it
Side effect is part of the AI Engineering Program, which teaches it with notes, a hands-on lab and an exam. The first lesson is free.