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 lvndry/jazz --skill create-personagit clone --depth 1 https://github.com/lvndry/jazzWrote 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/lvndry/jazz/create-persona)<a href="https://agentmods.dev/skills/lvndry/jazz/create-persona"><img src="https://agentmods.dev/badge/skills/lvndry/jazz/create-persona/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/lvndry/jazz/create-persona"><img src="https://agentmods.dev/badge/skills/lvndry/jazz/create-persona.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Rogue Agent · line 49 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
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 | $0.00038 | $0.01997 |
| Opus 5.5 | $0.00015 | $0.00799 |
| Sonnet 5.5 | $0.00008 | $0.00399 |
| Haiku 4.5 | $0.00004 | $0.00200 |
Grade A, and why
create-persona 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 29d 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 — 228 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Persona
Guide users through creating and refining custom personas: reusable system prompts with a name that decide how an agent works on any model.
When to Use
- User wants to create a new agent personality or communication style
- User asks "make an agent that talks like a xxx"
- User wants to customize how an agent responds
- User says "create a persona" or "define a character"
- User wants to edit or improve an existing persona
Core Concepts
A persona is a reusable system prompt with a name. It decides how an agent works: its voice, its priorities, what it does when a task is unclear. It says nothing about which model runs; the same persona can be attached to many agents on many models.
On disk it is one PERSONA.md file: YAML frontmatter plus the system prompt as the body.
| Field | Required | Purpose |
|---|---|---|
name |
Yes | Short identifier (letters, numbers, _, -). |
description |
Yes | One-line summary of the persona's character |
tone |
No | Label shown in listings, like "sarcastic" or "formal". Not sent to the model: put the voice in the body. |
style |
No | Label shown in listings, like "concise" or "technical". Not sent to the model: put it in the body. |
tools |
No | categories and/or deny lists. Narrows the tools an agent may use, never widens. |
Jazz keeps the body intact and appends one Jazz harness block for runtime rules. The persona's identity, tone, and priorities are treated as a binding contract for the whole conversation.
Placeholders
Three placeholders are filled in at run time. They are what let one file serve many agents. Always use them instead of hardcoding.
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.
- 29d ago Changed 0875e7226d9c
- 1mo ago Changed · -12 lines · +2 tokens per session 4f74f82453b0
- 1mo ago Changed · +5 lines efc99debdcfa
- 1mo ago First seen · 235 lines · 36 tokens per session scan A 25aa39c832cc
create-persona is a skill published in the GitHub repository lvndry/jazz (54 stars, last pushed yesterday), licensed MIT. It adds 38 tokens to every session and 1,997 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-30.
Other skills, from other repositories
system-prompts
Write system prompts, tool docs, and agent definitions. Project tag conventions + RFC 2119 keywords + dense compression. Use when authoring or editing any prompt the model reads.
imaging-data-commons
Query and download public cancer imaging data from NCI Imaging Data Commons using idc-index. Use for accessing large-scale radiology (CT, MR, PET) and pathology datasets for AI training or research. No authentication required. Query by metadata, visualize in browser, check licenses.
clinical-reports
Write comprehensive clinical reports including case reports (CARE guidelines), diagnostic reports (radiology/pathology/lab), clinical trial reports (ICH-E3, SAE, CSR), and patient documentation (SOAP, H&P, discharge summaries). Full support with templates, regulatory compliance (HIPAA, FDA, ICH-GCP), and validation…
clinical-decision-support
Generate professional clinical decision support (CDS) documents for pharmaceutical and clinical research settings, including patient cohort analyses (biomarker-stratified with outcomes) and treatment recommendation reports (evidence-based guidelines with decision algorithms). Supports GRADE evidence grading…
geo-database
Access NCBI GEO for gene expression/genomics data. Search/download microarray and RNA-seq datasets (GSE, GSM, GPL), retrieve SOFT/Matrix files, for transcriptomics and expression analysis.
flow-cytometry-analysis
Complete flow cytometry analysis pipeline. FCS file handling, compensation, manual/automated gating, immunophenotyping, CFSE proliferation analysis, cell cycle analysis (Dean-Jett-Fox), and apoptosis assays. Extends flowio with analytical workflows. For raw FCS parsing only use flowio.