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 mryll/skills --skill study-sessiongit clone --depth 1 https://github.com/mryll/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/mryll/skills/study-session)<a href="https://agentmods.dev/skills/mryll/skills/study-session"><img src="https://agentmods.dev/badge/skills/mryll/skills/study-session/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/mryll/skills/study-session"><img src="https://agentmods.dev/badge/skills/mryll/skills/study-session.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 | $0.00117 | $0.01670 |
| Opus 5.5 | $0.00047 | $0.00668 |
| Sonnet 5.5 | $0.00023 | $0.00334 |
| Haiku 4.5 | $0.00012 | $0.00167 |
Grade A, and why
study-session 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 1mo 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 — 75 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Study Session — recover and measure the theory of a subsystem
A session over real code in the repo. The user reads and explains; you probe and grade. The goal is Naur's "theory": the user can defend the subsystem's design, invariants, and failure modes without help. Two modes:
- Deep (45-60 min): learn or repair one subsystem/unit. Default for
not-assessed,practiced, orcode-changedtargets. - Checkpoint (10-15 min): measure retention of a due unit — one cold reconstruction + one transfer scenario. Default when the row's next-due date expired.
Core principle: cold evidence is graded separately from learning. What the user produces BEFORE your corrections is what gets measured; what they learn after counts as learning, never as certification.
Finding the comprehension map
The map's schema (columns, status vocabularies, event format, spacing rule) lives in the user's knowledge wiki — this skill defers to it. To locate the map:
- Resolve the wiki root: follow the
~/.claude/work-wikisymlink if present; otherwise ask once and offer to create that symlink. - Glob
**/projects/*-comprension.md(or the wiki's declared comprehension-map convention) withkind: comprehension-mapfrontmatter; match the current repo/workspace (git remote or basename) against each map's repo/paths column — one project may span several repos. - Exactly one match → use it. None → derive the path from the project name per the wiki's convention, confirm with the user, create from the wiki's schema template. Several → ask.
No wiki or schema at all → offer a minimal inline map: | Subsystem | Repo/paths | Current evidence | Scope | Last passed | Next due | Gaps | with outcome (not-assessed | practiced | partial | defensible) and validity (current | evidence-expired | code-changed | code-currentness-unknown) vocabularies.
Target selection (risk-first)
Propose ONE target with a one-line reason, in this priority order — the user can override:
- Relevant code changed since the row's last evidence SHA (
code-changed). - An open gap implicated by a recent MR or incident.
- High-blast-radius unit overdue.
- Any other overdue unit.
- Untested low-risk units.
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.
- 1mo ago First seen · 75 lines · 117 tokens per session scan A 839b8c6b1afd
study-session is a skill published in the GitHub repository mryll/skills (6 stars, last pushed 4d ago), licensed MIT. It adds 117 tokens to every session and 1,670 once invoked, about $0.0005 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 2026-08-31.
Other skills, from other repositories
lesson
Produce or continue a deep-dive learning-track lesson (a focused mini-course on a hard subject the project needs), or review the user's track exercise work. Use when the user asks for the next lesson, help with a track exercise, or to start a new track.
cangjie-skill
A process for turning a book, course, podcast, interview, long video, or other long material into reusable instructions for an AI agent. It extracts methods and principles, checks them, and packages them as skills.
reading-metaskill
A reading and learning guide based on building a regular reading habit, choosing books, and understanding difficult subjects through original works and explanation.
principal-agent
A Chinese-language guide based on the principal-agent idea: the person who owns a decision or its result may have different incentives from someone acting on another person's behalf. It applies this lens to jobs, companies, and partnerships.
scaffold-exercises
A template builder for coding exercises, organized into sections and exercises with problem, solution, and explanation folders. It creates the files and structure expected by the project’s lint checker.
aiwg-guide
Contextual AIWG help — explains current version features, answers how-to questions, routes live queries to the steward.