Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/majiayu000/spellbooknpx agentmods add skills/majiayu000/spellbook/skill-lifeguardWrote 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/majiayu000/spellbook/skill-lifeguard)<a href="https://agentmods.dev/skills/majiayu000/spellbook/skill-lifeguard"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/skill-lifeguard/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/majiayu000/spellbook/skill-lifeguard"><img src="https://agentmods.dev/badge/skills/majiayu000/spellbook/skill-lifeguard.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00092 | $0.01067 |
| Opus 5 | $0.00046 | $0.00534 |
| Sonnet 5 | $0.00018 | $0.00213 |
| Haiku 4.5 | $0.00009 | $0.00107 |
Grade A, and why
skill-lifeguard 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 8d 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 — 128 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Skill Lifeguard
Use this skill to make an existing or new skill self-maintaining enough for real
agent work. It complements skill-audit and skill-creator: use this skill for
the reliability contract, then use those skills for library fit and authoring.
Read references/examples.md when you need example contract wording. Use
assets/reliable-contract-template.md when drafting a reusable section.
Reliable Skill Contract
Every high-value workflow skill should either include these five elements or record why an element is intentionally deferred:
| Element | Required Evidence |
|---|---|
| Explicit negative examples | Named forbidden behaviors and concrete alternatives. |
| Verification checkpoints | Pass/fail checks after important phases, not only at the end. |
| Machine-checkable done conditions | Commands, assertions, artifacts, or state queries from the current session. |
| Replay or smoke hooks | A small way to rerun or sample the workflow, plus a log-to-patch loop. |
| Drift signal detection | Observable signs that the skill is stale, undertriggering, overtriggering, or producing false success. |
Workflow
- Search before creating or moving skill files.
- Read the target skill and nearby docs that define its expected workflow.
- Classify the skill maturity:
manual: workflow still needs human validation.skill: manually validated and packaged as reusable instructions.automation: repeatedly reliable and safe enough for scheduled or hook-driven use.
- Score the five contract elements as
present,partial,missing, ordeferred. - Patch the smallest durable home:
SKILL.mdfor routing and boundaries,references/for long examples,scripts/for deterministic checks,assets/ortemplates/for reusable report shapes. - Run repository validation and any skill-specific smoke check.
Operating Contract
- Direct actions: audit skill files, draft contract gaps, patch local skill instructions, and run local validation.
- Escalate before: publishing skills, installing into user runtime directories, deleting user files, changing secrets, or promoting manual workflows into scheduled automation.
- Evidence-backed pushback: refuse reliability claims that lack fresh verification, replay hooks, or drift signals.
- Feedback loop: turn repeated corrections, false-success signals, or failed smoke runs into a skill patch and rerun validation.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 8d ago First seen · 128 lines · 92 tokens per session scan A 30fbf3f43577
skill-lifeguard is a skill published in the GitHub repository majiayu000/spellbook (278 stars, last pushed yesterday), licensed MIT. It adds 92 tokens to every session and 1,067 once invoked, about $0.0005 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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