# AI Instruction and Prompt Checker

Paste instructions for an AI assistant or agent and find conflicting rules, vague wording and duplicated sections.

- URL: https://toolstackhub.co.uk/tools/agent-instruction-checker/
- Category: Text Tools
- Price: free, no sign-up
- Privacy: runs in the browser; input is not uploaded
- Last updated: 2026-10-08

## About
Long system prompts, custom instructions and agent rule files often contradict themselves. Paste yours and the checker looks for "always" and "never" rules that clash, vague wording, near-duplicate lines, shouting in capitals, very long lists and missing parts such as an output format or examples. It uses text rules rather than AI, so it flags things for you to review rather than judging quality. The text stays in your browser.

## How to use
1. Paste or type your input into the box above.
2. Choose any options you need. Results update as you type.
3. Copy the result with the Copy button.

## FAQ
**Does it use an AI model?** No. It compares your lines with text rules (overlapping words, opposite style words, vague terms), so it runs privately in your browser and is quick, but it cannot understand meaning perfectly.

**Why are conflicting rules a problem?** When two rules disagree, the assistant has to guess which one to follow, and it may choose differently each time. Giving priorities or conditions removes the guesswork.

**Is the AI Instruction and Prompt Checker free?** Yes, with no sign-up or limits.