magnus919_agent-skills/AGENTS.md

AGENTS.md — Agent Guide for agent-skills

This file tells AI agents how to load and use skills from this repository. Skills in this repo follow the Agent Skills open format — a standardized way to give agents new capabilities through structured markdown files.

Format Compliance

Every skill in this repository conforms to the Agent Skills specification:

Requirement	Rule
Directory	Each skill in its own directory named by the skill
Entry point	SKILL.md with YAML frontmatter + markdown body
name field	Lowercase, hyphens only, matches parent directory name
description field	Trigger-oriented, starts with an imperative verb, defines both positive and negative trigger boundaries
Progressive disclosure	Core instructions in SKILL.md (< 500 lines, < 5,000 tokens), supporting material in references/, templates/, scripts/
File references	Relative paths from skill root, one level deep
Human-readable README	README.md in skill root — required for every skill. See README Format below

README Format

Every skill directory MUST contain a README.md written for a human audience (not an AI agent). The README explains what the skill does and why someone would want to install it. It is the public face of the skill — the first thing a human sees when browsing the repository.

Required Sections

Section	Purpose
Title	Skill name + one-line summary of what it does
Why Install This Skill	2-3 paragraph pitch answering "what problem does this solve for me?" and "what can my agent do after installing this?" — written in plain language, not format docs
What You Get	Table listing directory contents (scripts, references, templates, assets) and what each provides
Quick Start	Minimal setup: env vars to export, first command to run (omit for reference-only skills)
Triggers	List of trigger conditions that tell someone when to load this skill
Requirements	Dependencies, API keys, Python version, system tools

Style Guidance

• Lead with benefit, not implementation. Answer "what does this do for me?" before "what tech is it built on?"
• Be concrete. Show real command examples with expected output. Avoid abstract descriptions.
• Assume the reader is human. No agent instructions, no JSON schemas, no progressive disclosure notes. Those go in SKILL.md.
• Keep it scannable. Use tables, code blocks, and bullet lists. A human should grasp the skill's purpose in 10 seconds.
• One page or less. A README that takes more than a minute to read is too long. Save depth for SKILL.md.

Example

See data-scientist/README.md or any skill in this repository for the canonical format.

State-Modifying Skills

Skills that change external state must say so explicitly and use this gate before the first mutation:

Confirm the target, scope, and rollback path before acting. Read-only discovery may proceed without confirmation.

Destructive operations still require an explicit user directive; this convention does not authorize deletion, privilege changes, or irreversible cleanup.

Failure-Mode Routing

For problem-pattern routing, start with FAILURE-MODE-INDEX.md.

How to Load Skills

Skills are loaded progressively in three stages:

Stage 1 — Metadata

At session start, read each skill's name and description from frontmatter. This takes ~100 tokens per skill and lets you know what's available without loading full content.

# Example metadata (from cli-builder/SKILL.md)
name: cli-builder
description: >-
  Build or refactor CLI tools designed for AI agent consumption: non-interactive,
  flag-driven, idempotent, with --json output and --dry-run preview.

Stage 2 — Full Instructions

When a user's request matches a skill's description keywords, load the full SKILL.md. The body contains step-by-step instructions, examples, and gotchas. Do not load skills preemptively — only load when triggered.

Stage 3 — Supporting Files

Reference files (references/, templates/, scripts/) are loaded on demand. The SKILL.md tells you when to read each one. Do not load all references at activation time — following the triggers preserves context.

Reading Order

If this is your first session with this repo, read these in order:

1. agent-skills/SKILL.md — The Agent Skills format reference. Read this first to understand the format.
2. README.md — Skill index with descriptions. Use to discover which skill to load.
3. Individual skill SKILL.md files as triggered by the user's task.

Skill Routing

Use each skill's description field as the primary routing source. For keyword lookup, see the skill trigger index.

Use-When Sections

Every skill description must start with an imperative verb and define both when to load it and when not to. Skills with meaningful overlap should also include a ## When not to use section naming the nearest alternative or prerequisite. Keep these sections trigger-oriented and concise; implementation details belong in references. The repository's quality validator enforces these requirements on changed skills.

Eval Requirements

evals/evals.json is a versioned contract owned by this repository; it is not part of the normative Agent Skills specification. The declarative contract is schemas/evals-v1.schema.json, and assertions is the canonical case field. Do not substitute or alias expectations.

Every new skill must include a schema-versioned evals/evals.json with at least five representative output-quality cases. Each case needs a stable ID, realistic prompt, expected outcome, and observable assertions. Renaming an eval ID breaks durable evidence references; do not attempt heuristic rename matching. Trigger-only checks (should-trigger / should-not-trigger probes) are harness-specific and belong in a separate test set, not in evals/evals.json.

Coverage reports these five states separately:

State	Evidence required
manifest_present	evals/evals.json exists. This alone does not prove behavioral quality.
schema_valid	The manifest passes the repository's v1 structural and semantic validation.
executable_grader_bindings_present	Not assessed in v1. Requires a separate versioned grader-binding contract.
recent_run_evidence_present	Not assessed in v1. Requires a separate versioned provenance/freshness contract.
release_gated_evidence_present	Not assessed in v1. Requires a separate versioned release-gate contract.

v1 only covers manifest structure and semantic validity. It does not establish runtime provenance or release-gate evidence. Validate the contract and run its focused tests with:

python3 -m venv .venv
. .venv/bin/activate
python3 -m pip install -r requirements-dev.txt
python3 scripts/test-eval-validation.py
python3 scripts/validate-evals.py

Existing skills are grandfathered via scripts/grandfathered-skills.txt. As schema-valid manifest coverage climbs past 25%, modified skills without valid manifests receive a warning; past 50%, they fail CI. The coverage report is available via python3 scripts/eval-coverage.py. The ratchet is enforced in CI via python3 scripts/eval-coverage.py --modified-from <base-sha> on every pull request. A skill is considered modified when any tracked file under its directory changes, not only SKILL.md. Schema-valid manifest coverage must not decrease between the base revision and the candidate; a decrease fails CI.

Best Practices

Do Load by Trigger

The description field is the trigger mechanism. If the user's request contains keywords matching a skill's description, load that skill. If multiple skills match, load the most specific one.

Don't Load Everything at Startup

Loading every skill at session start wastes context. Let the conversation trigger loading. Skills load in ~100 tokens (metadata) and only expand when needed.

Follow Progressive Disclosure

When a skill body tells you to read a reference file only under specific conditions ("Read this if the API returns a 500"), do not read it proactively. Reference files are for specific edge cases, not general instruction.

Completion and Exit Conditions

Skills that perform diagnosis, planning, or multi-step work must state when they are complete and when to stop. A valid exit condition is an observable artifact or a bounded escalation, such as: deliver the requested file, confirm the current setup is adequate, or stop after three non-converging diagnostic passes and report the evidence.

Validate Your Output

When creating or modifying a skill in this repo, validate against the format:

• name matches parent directory name
• description is 1-1024 chars, non-empty, starts with an imperative verb, and defines a negative boundary
• Body under 500 lines and 5,000 tokens
• All file references use relative paths from skill root
• Frontmatter YAML is valid
• README.md exists in the skill root with all required sections (see README Format above)
• README is written for humans — no agent instructions, JSON schemas, or progressive disclosure notes in the README. Those belong in SKILL.md.
• evals/evals.json exists with at least five output-quality cases for new skills (see Eval Requirements)
• python3 scripts/validate-evals.py accepts every present eval manifest

Generated Artifacts

This repository tracks generated catalog files (.claude-plugin/marketplace.json, .codex-plugin/plugin.json, .agents/plugins/marketplace.json, llms.txt). CI validates that these are current; it does not regenerate them. If CI reports a stale artifact, regenerate locally:

ruby scripts/gen-claude-marketplace.rb --write
ruby scripts/gen-codex-plugin.rb --write
ruby scripts/gen-llms-txt.rb --write

Each script also runs in check mode (without --write) to verify freshness.

Respect Attribution

Some skills in this repo are adapted from other open-source projects. Attribution is maintained in the source field. Do not remove or modify attribution.

Troubleshooting

Skill not loading when expected: The description field may need trigger keyword updates. Check that the user's phrasing overlaps with the skill's description vocabulary.

Skill body too large: The agent's context window may be full. The spec recommends under 5,000 tokens per skill. If a skill is exceeding this, its content can be further split into references.

Reference file not found: All file references use relative paths from the skill's directory root. If a reference is missing, check that the file exists at the path specified.