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 bearded-illirian/trailmark --skill check-firstgit clone --depth 1 https://github.com/bearded-illirian/trailmarkWrote 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/bearded-illirian/trailmark/check-first)<a href="https://agentmods.dev/skills/bearded-illirian/trailmark/check-first"><img src="https://agentmods.dev/badge/skills/bearded-illirian/trailmark/check-first.svg" alt="Measured on agentmods" 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 | $0.00098 | $0.01107 |
| Opus 5 | $0.00049 | $0.00553 |
| Sonnet 5 | $0.00020 | $0.00221 |
| Haiku 4.5 | $0.00010 | $0.00111 |
Grade A, and why
check-first 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 4d 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 — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Check-First Protocol
Runs after a decomposition step in any workflow (e.g. after proposing epics for a brief, or blocks for a specification). Verifies that every requirement from the source document is covered by at least one proposed unit.
Step 1 — Extract requirements
From the already-read requirements document (brief, specification, technical description, product doc) extract every requirement. Look in sections like:
- Scope / What's included
- Acceptance criteria
- What must exist
- Functional requirements
- Non-functional requirements
Each requirement is one row. Don't duplicate near-identical items — merge them if the essence is the same.
Step 2 — Output a coverage table
Requirements coverage check:
┌─────┬────────────────────────────────────┬──────────────┬────────────┐
│ # │ Requirement │ Unit │ Status │
├─────┼────────────────────────────────────┼──────────────┼────────────┤
│ 1 │ [requirement from source doc] │ Unit N │ ✅ Covered │
│ 2 │ [requirement from source doc] │ Unit N │ ✅ Covered │
│ 3 │ [requirement from source doc] │ — │ ⚠️ Gap │
└─────┴────────────────────────────────────┴──────────────┴────────────┘
"Unit" = the smallest labelled thing in your decomposition: an epic, a block, a task — whatever the current workflow produces.
Step 3 — Decision
If every row is ✅:
✅ All requirements covered — continuing.
Proceed without pause.
If there are ⚠️ gaps:
⚠️ N gap(s) found. Options:
1. Add to an existing unit [Unit X]
2. Create a new unit
3. Move to backlog — not part of this cycle
Wait for user decision per gap. After decisions land — update the unit list and continue.
Rules
- Don't skip even when the decomposition looks obviously complete
- On gaps — don't proceed without a user decision
- Extract requirements from the source text, don't invent them
- The point of the protocol is a paper trail: even a "no gaps" result is a first-class artifact — future readers see what was checked
What ships with it
1 file 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.
- 4d ago Changed f430f24ee12d
- 8d ago First seen · 157 lines · 98 tokens per session scan A de34f34ad841
check-first is a skill published in the GitHub repository bearded-illirian/trailmark (19 stars, last pushed 6d ago), licensed MIT. It adds 98 tokens to every session and 1,107 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 2026-08-30.
Other skills, from other repositories
mission-control
Interact with Mission Control — AI agent orchestration dashboard. Use when registering agents, managing tasks, syncing skills, or querying agent/task status via MC APIs.
ceo-delegation
A task-delegation workflow that tells an agent to assign work to sub-agents, monitor their progress, and review their results rather than doing the work itself.
change-review
Validate CRM/PM changes before PR.
channel-truth-run
Automatic channel and contact synchronization.
client-discovery
Analyze client automation/AI requests into structured scoping with hours, pricing, and priorities.
client-workspace
Create client folder structure in Drive, share docs, check permissions before calls.