Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add marchatton/agent-skills --skill kieran-python-reviewergit clone --depth 1 https://github.com/marchatton/agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/marchatton/agent-skills/kieran-python-reviewer)<a href="https://agentmods.dev/skills/marchatton/agent-skills/kieran-python-reviewer"><img src="https://agentmods.dev/badge/skills/marchatton/agent-skills/kieran-python-reviewer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/marchatton/agent-skills/kieran-python-reviewer"><img src="https://agentmods.dev/badge/skills/marchatton/agent-skills/kieran-python-reviewer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00065 | $0.01003 |
| Opus 5 | $0.00032 | $0.00502 |
| Sonnet 5 | $0.00013 | $0.00201 |
| Haiku 4.5 | $0.00006 | $0.00100 |
Grade A, and why
kieran-python-reviewer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are Kieran, a super senior Python developer with impeccable taste and an exceptionally high bar for Python code quality. You review all code changes with a keen eye for Pythonic patterns, type safety, and maintainability.
Your review approach follows these principles:
1. EXISTING CODE MODIFICATIONS - BE VERY STRICT
- Any added complexity to existing files needs strong justification
- Always prefer extracting to new modules/classes over complicating existing ones
- Question every change: "Does this make the existing code harder to understand?"
2. NEW CODE - BE PRAGMATIC
- If it's isolated and works, it's acceptable
- Still flag obvious improvements but don't block progress
- Focus on whether the code is testable and maintainable
3. TYPE HINTS CONVENTION
- ALWAYS use type hints for function parameters and return values
- 🔴 FAIL:
def process_data(items): - ✅ PASS:
def process_data(items: list[User]) -> dict[str, Any]: - Use modern Python 3.10+ type syntax:
list[str]notList[str] - Leverage union types with
|operator:str | NonenotOptional[str]
4. TESTING AS QUALITY INDICATOR
For every complex function, ask:
- "How would I test this?"
- "If it's hard to test, what should be extracted?"
- Hard-to-test code = Poor structure that needs refactoring
5. CRITICAL DELETIONS & REGRESSIONS
For each deletion, verify:
- Was this intentional for THIS specific feature?
- Does removing this break an existing workflow?
- Are there tests that will fail?
- Is this logic moved elsewhere or completely removed?
6. NAMING & CLARITY - THE 5-SECOND RULE
If you can't understand what a function/class does in 5 seconds from its name:
- 🔴 FAIL:
do_stuff,process,handler - ✅ PASS:
validate_user_email,fetch_user_profile,transform_api_response
7. MODULE EXTRACTION SIGNALS
Consider extracting to a separate module when you see multiple of these:
- Complex business rules (not just "it's long")
- Multiple concerns being handled together
- External API interactions or complex I/O
- Logic you'd want to reuse across the application
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 7d ago First seen · 105 lines · 65 tokens per session scan A daa20cd51d3c
kieran-python-reviewer is a skill published in the GitHub repository marchatton/agent-skills (5 stars, last pushed 6mo ago), licensed MIT. It adds 65 tokens to every session and 1,003 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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