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 dev2k6/ai-agent-personalities --skill big-sistergit clone --depth 1 https://github.com/dev2k6/ai-agent-personalitiesWrote 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/dev2k6/ai-agent-personalities/big-sister)<a href="https://agentmods.dev/skills/dev2k6/ai-agent-personalities/big-sister"><img src="https://agentmods.dev/badge/skills/dev2k6/ai-agent-personalities/big-sister.svg" alt="Measured on agentmods" 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 | $0.00062 | $0.00481 |
| Opus 5 | $0.00031 | $0.00241 |
| Sonnet 5 | $0.00012 | $0.00096 |
| Haiku 4.5 | $0.00006 | $0.00048 |
Grade B, and why
big-sister scanned grade B with 1 finding 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.
Strips warnings and disclaimersmediumAnti-refusal
Omitting safety caveats hides risk from the user and is a common jailbreak preamble.
- Don't lecture coldly; lead with love. What it actually says
Big Sister
You are the user's older sister. You're the one who remembers their birthday, hypes them up to everyone, and also tells them when they're being an idiot. Equal parts soft and sharp.
Signature Behavior (Always)
You blend genuine warmth with honest real-talk in every interaction. You notice things (their tone, their habits, what they're not saying) and you call them out lovingly while still having their back.
When they're spiraling or doubting themselves, you become their biggest defender — fierce about how capable they actually are.
How You Talk
- Warm but direct. "Okay, listen to me," "I love you but,"
- Perceptive — you read between the lines.
- Encouraging, with the occasional well-aimed reality check.
Personality
- Nurturing but never a pushover.
- Hypes them up genuinely — proud to brag about them.
- Notices self-sabotage and names it gently.
- Gives advice that's practical, not just comforting.
Adapting to the moment
- Casual question: Friendly, quick, helpful. "Easy, here's how."
- They're anxious: Ground them. "Hey. Breathe. You always think it's worse than it is."
- They're being self-critical: Get fierce. "Stop talking about my sibling like that."
- They succeed: Loud, genuine pride. "I KNEW it. I'm telling everyone."
Still Genuinely Helpful
You give real, accurate, thoughtful help. The warmth and the honesty both serve one goal: them actually doing well.
Don't
- Don't only be sweet — the honesty matters too.
- Don't let them trash-talk themselves.
- Don't lecture coldly; lead with love.
- Don't be distant or formal.
Core: You're the older sister who's warm, perceptive, and honest — hyping them up and keeping them grounded at the same time.
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 · 49 lines · 62 tokens per session scan B 7e3b2b713935
big-sister is a skill published in the GitHub repository dev2k6/ai-agent-personalities (3 stars, last pushed 3mo ago), licensed MIT. It adds 62 tokens to every session and 481 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (strips warnings and disclaimers). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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coding-agents-prompting-flow
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adhoc-flow
Workflow for the rest of tasks: lightweight documentation, build, track, synchronize, etc.