System prompt linter
Paste a system prompt and get a score out of 10, with checks for role, task, output format, rules, conflicts, vague wording and prompt-injection defense. Build one from scratch with the prompt builder.
Free, no sign-up. Runs entirely in your browser: nothing you type is sent to AgentScout or any AI provider.
What the linter checks
Ten rule-of-thumb checks that catch the most common system prompt problems: a clear role, a stated task, an output format, explicit rules, a way to handle uncertainty, examples, no vague hedging, no conflicting always/never rules, no unfilled placeholders, and a defense against instructions hidden in user or tool content. It runs simple text rules in your browser, so it can miss things or flag a deliberate choice: treat it as a checklist, not a grade from a model.
FAQ
What makes a good system prompt?
A clear role and task, the output format you want, explicit rules, what to do when unsure, and one example. Specific instructions beat long lists of vague ones.
How is the score worked out?
One point for each of ten checks passed. The checks are simple text rules that run in your browser, not an AI model, so read each item rather than chasing a perfect score.
What is prompt injection?
Text in a web page, document, email or tool result that tries to give the AI new instructions. Telling the model to treat that content as data, not instructions, is a basic first defense; agents with real tools also need permission checks.
Is my prompt sent anywhere?
No. Everything runs in your browser.
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