promptguard

name	promptguard
description	Use when auditing system prompts, agent prompts, router prompts, tool/function-call prompts, or prompts that cause inconsistent, unsafe, malformed, or surprising LLM behavior.
metadata	{"short-description":"Audit prompts as executable contracts"}

PromptGuard

Audit prompts as executable contracts, not writing style. The core job is to compare what the prompt literally says with what the user expects the model to do.

When Triggered

Use this skill when the user shares, writes, reviews, debugs, or asks to improve:

• system prompts
• agent/router prompts
• evaluator prompts
• tool or function-call instructions
• prompt files in a repo

Workflow

1. Identify the surface: TUI, web chat, API, router, tool call, evaluator, or agent persona.
2. Extract contracts: role, task, input, context, output, boundaries, safety escalation, memory/state, tool schema, evaluation.
3. Flag failures: missing contract, conflicting instruction, ambiguous boundary, passive safety escalation, role drift, provider schema mismatch. Also flag vague intent, later-rule override, context retention illusion, and false certainty. For coding/build prompts, flag missing responsibility, owned surface, constraints, verification, and accountability report.
4. Return findings as: Severity | Evidence | Impact | Missing/Conflicting Contract | Clarification Contract | Questions to Ask | Approval Contract | Fix Draft

Clarification questions must be generated from the missing decision point. Do not hardcode them to one example like reports.

Pre-Write Guard

If the user asks to add, save, insert, seed, update, or write a prompt, audit the proposed prompt before editing files.

For pasted prompt text:

printf '%s' '<prompt text>' | python3 skills/promptguard/scripts/audit_prompt.py - --format markdown

If high or critical findings appear, do not write yet. Show findings and ask for explicit approval or offer a fixed draft.

Deterministic Audit

If the prompt is in a local file, run this before finalizing:

python3 skills/promptguard/scripts/audit_prompt.py path/to/prompt-file --format markdown

If this skill is installed into $CODEX_HOME/skills/promptguard, run the script from that installed path instead.

Do not stop after discovering prompt files. Discovery is not completion. If a prompt-like file exists and the script exists, running the script is mandatory.

If the user asks for a report without naming a file, run:

python3 skills/promptguard/scripts/audit_repo.py . --format markdown

Severity

• critical: unsafe, illegal, or harmful behavior risk.
• high: privacy, routing, parsing, or tool-call breakage.
• medium: inconsistent UX or agent boundary drift.
• low: maintainability or clarity issue.

Prefer concrete contract fixes over generic prompt advice.