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 Tibsfox/gsd-skill-creator --skill stellar-spectroscopygit clone --depth 1 https://github.com/Tibsfox/gsd-skill-creatorWrote 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/tibsfox/gsd-skill-creator/stellar-spectroscopy)<a href="https://agentmods.dev/skills/tibsfox/gsd-skill-creator/stellar-spectroscopy"><img src="https://agentmods.dev/badge/skills/tibsfox/gsd-skill-creator/stellar-spectroscopy/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/tibsfox/gsd-skill-creator/stellar-spectroscopy"><img src="https://agentmods.dev/badge/skills/tibsfox/gsd-skill-creator/stellar-spectroscopy.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 | $0.00084 | $0.03707 |
| Opus 5.5 | $0.00034 | $0.01483 |
| Sonnet 5.5 | $0.00017 | $0.00741 |
| Haiku 4.5 | $0.00008 | $0.00371 |
Grade A, and why
stellar-spectroscopy 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.
The source is not reproduced here
A licence we could not identify
The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.
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 · 201 lines · 84 tokens per session scan A 406f9549a664
stellar-spectroscopy is a skill published in the GitHub repository Tibsfox/gsd-skill-creator (71 stars, last pushed 3mo ago), with no licence file. It adds 84 tokens to every session and 3,707 once invoked, about $0.0003 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 2026-09-03.
Other skills, from other repositories
migration-patterns
Safe schema-migration patterns for systems under live traffic — expand/contract, backfill, double-write, shadow-read, online DDL. Use when authoring, reviewing, or sequencing a migration that can't take a maintenance window.
token-economy
Rubric for keeping Claude Code sessions cheap without losing quality — model tiering, cache hygiene, Read discipline, MCP pruning, subagent isolation. Use when cost feels wrong, before setting a budget, or when onboarding a teammate.
api-design
REST and GraphQL API design conventions — resource modeling, pagination, error envelopes, versioning, idempotency. Use when adding, changing, or reviewing endpoints.
debug-playbook
Hypothesis-driven debugging — reproduce, hypothesize, probe, locate, fix, guard. Use when something is broken and you don't yet know why.
test-patterns
Reference for writing tests that actually protect against regressions — deep assertions over spies, table-driven tests, fixture hygiene, AAA structure. Use when writing, reviewing, or refactoring tests.
observability-checklist
What good observability looks like — structured logs, trace spans, metrics, correlation ids, and the instrumentation rules that turn logs into answers. Use when adding a feature, reviewing a service, or debugging a prod issue.