> For the complete documentation index, see [llms.txt](https://docs.questflow.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.questflow.ai/financial-harness/what-are-filters.md).

# What Are Filters?

**Short answer:** Filters are hard gates. A signal can be weak and you still look. A failed required filter means pass — the skill should not force a trade. In the Investor Skills schema a filter is `required`, `disqualifier`, or an expression like `"< 0.5"`.

## Examples

* Buffett: `durableMoat: required`, `consistentFCF: required`
* Universe liquidity: reject if you cannot exit
* Forensic skills: related-party webs as disqualifiers

Filters keep the model from “talking itself into” a name outside the investor’s rules. That is how a harness stays a judgment system instead of a chatbot.

Related: Signals · Universe · Investment schema

*Nothing here is financial advice.*