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 agentmods add instructions/langfuse/skills/agents-mdgit clone --depth 1 https://github.com/langfuse/skillsWhat 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 | $0.01518 | $0.01518 |
| Opus 5 | $0.00759 | $0.00759 |
| Sonnet 5 | $0.00304 | $0.00304 |
| Haiku 4.5 | $0.00152 | $0.00152 |
Grade A, and why
skills AGENTS.md 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 2d 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 — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Instructions
Adding or Improving a Skill Use Case
FOLLOW THESE INSTRUCTIONS RELIGIOUSLY. After every edit you make, come back to these principles and judge critically whether you adhered to them. Fix your edits if not.
-
Only add a use case if it beats the docs. If an agent can already serve the user by fetching the Langfuse docs, add nothing. Reserve new content for where docs fall short and the agent needs extra context. Every addition is maintenance surface and dilutes the skill.
-
You should almost never touch the top-level frontmatter
descriptioninSKILL.md. It only controls whether the skill is invoked, and a user asking about a use case already mentions Langfuse or evaluation — which triggers it. Keep it short; in-skill routing handles the rest. -
Put "when to use" guidance in exactly two places: exactly one one-line entry per reference in the
## Use case specific referenceslist inSKILL.md, and thedescriptionin the reference file's frontmatter. Nowhere else — no prose routing section, no "when to use" section in the reference body. A reference body is read only after the agent already chose to open it, so routing text there is dead weight. -
Every reference file's frontmatter must declare a
metadata.required_accesslist — the kinds of access an agent needs to execute that reference. Use only these tokens, and reuse them consistently across files:CODEBASE— reads or edits the user's source codeLANGFUSE_PROJECT_INTERFACE— reaches the Langfuse project via CLI / API / MCP commandsLANGFUSE_PROJECT_SCRIPT— runs SDK code that connects to the Langfuse backend (needs network)GITHUB— operates on GitHub via theghCLI
-
Every line must earn its place. Add only what's useful or what an agent couldn't infer on its own. Cut filler, restatements, self-explanatory steps, and anything the agent will already have from the relevant docs or task context. Keep new use-case references at 100 lines or fewer, including frontmatter; this is a maximum, if you exceed this length, you are likely producing slop.
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.
- 2d ago First seen · 69 lines · 1,518 tokens per session scan A 4abe8d3026c5
skills AGENTS.md is an instructions file published in the GitHub repository langfuse/skills (266 stars, last pushed 4d ago), licensed MIT. It adds 1,518 tokens to every session, about $0.0076 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 instructions, from other repositories
spellbook AGENTS.md
Instructions for majiayu000/spellbook, covering spellbook agent contract, routing, scope rules, threads long-run guardrails and validation.
open-supermarkets AGENTS.md
Instructions for abracadabra50/open-supermarkets, covering agent integration guide, supported frameworks, quick integration, 1. add as skill and 2. agent calls commands.
helm copilot-instructions.md
Instructions for PetePeter/helm, covering gamepad-cli-hub — copilot instructions, project purpose, system overview, data flow pipeline and key controls.
fusion-skills AGENTS.md
AGENTS.md instructions for CrowdStrike/fusion-skills, covering agents.md, what this is, prerequisites, repository structure and skills ecosystem.
aeon CLAUDE.md
Instructions for aeonfun/aeon, covering aeon, how aeon works, strategy, voice and soul file hierarchy (read in this order).
ESAA-Core AGENTS.md
Instructions for elzobrito/ESAA-Core, covering agents.md — contrato operacional codex/esaa, 1. autoridade e termos, 2. cli e runner, ou configure o runner uma vez por sessão and 3. concorrência.