# Reliability

> System properties that keep agent behavior predictable, recoverable, and verifiable.

- [What should a search API return to an agent?](https://www.searchforagents.com/blog/what-should-a-search-api-return-to-an-agent) — Valyu, Exa, and Parallel return different combinations of links, passages, dates, and diagnostics. Here is the evidence contract an agent needs to build around their results.
- [When can an agent trust a web search result?](https://www.searchforagents.com/blog/when-can-an-agent-trust-a-web-search-result) — A 2026 UK holiday calendar says Scotland has nine bank holidays; official records list ten. Follow a search result to its source and learn a five-check method for verifiable answers.