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Get Started Free →Load when creating a new Agent Skill from a workflow, project rule, repeated task, SOP, execution trace, success/failure pattern, human office process, Codex/Hermes harness task, or project-specific knowledge that should become a reusable SKILL.md package.
| Test case | Without → With | Effect | Δ tokens | Δ turns |
|---|---|---|---|---|
| case-01 | ✗→✓ | ▲ Improved | 29% | 0% |
| case-19 | ✗→✓ | ▲ Improved | 79% | 0% |
| case-07 | ✗→✓ | ▲ Improved | 71% | 0% |
| case-10 | ✗→✓ | ▲ Improved | 258% | 0% |
| case-14 | ✗→✓ | ▲ Improved | 53% | 0% |
Use this skill to turn a repeatable workflow or project practice into a new Agent Skill that another agent can load, understand, execute, and evaluate.
This skill creates a candidate skill package. It does not claim the skill is production-ready until evaluation evidence exists.
Collect or infer:
If evidence is thin, create an experimental skill and mark missing evidence in the creation report.
Create a skill only when at least one condition is true:
Do not create a skill for one-off facts, unverifiable preferences, private details that cannot be sanitized, or tasks that require unstructured real-time human judgment.
Classify evidence before writing:
| Bucket | Use | |---|---| | success_positive | Extract procedures, tool order, verification habits, and reusable checklists. | | failure_recovered | Extract failure mechanisms, repair paths, and fallback logic. | | failure_unrecovered | Identify missing capability, missing tool, or boundary that the skill must expose. | | human_gold | Define human baseline, expected quality, and acceptance criteria. |
Prefer a mixed pool. Do not build a skill only from failures unless the user explicitly wants a narrow remediation skill.
Decide the capability boundary:
create: no existing skill covers the capability.extend: an existing skill covers the domain but lacks the observed failure mechanism.split: the proposed skill would make an existing skill too broad.merge: multiple proposed skills overlap and should become one capability package.The proposed skill must name the behavior change it should cause in the agent, not just the topic it describes.
Write SKILL.md as a compact task contract:
textGoal Inputs Workflow Failure Modes Verification Boundaries Runtime Resources Output Contract Handoff
Use a minimal contract for low-risk text-only skills. Use a full contract when the skill touches tools, files, external systems, privacy, publication, deployment, finance, legal, or multi-agent workflows.
The frontmatter description must be a routing trigger. It should say when to load the skill, using task situations users actually say.
Keep SKILL.md lean. Move detail into resources:
references/ for long rules, domain notes, paper digests, examples of good/bad traces, and policy context.examples/ for sample inputs, expected outputs, and realistic prompts.scripts/ only when deterministic checks or repeated fragile operations exist.evals/ for routing, behavior, and outcome tasks.Every resource referenced in SKILL.md must have a clear load condition. Do not write machine-local absolute paths into reusable skill files. Use relative paths inside the skill package and cite public repository paths or paper names in references.
For each recurring failure, write an if/then recovery rule:
textIf <detectable symptom>, first <repair action>. If still failing, <fallback or handoff>.
Avoid vague instructions such as "be careful", "consider", "use judgment", or "handle appropriately" unless paired with concrete checks.
Create or request:
If no evaluation assets exist, include experimental status and a clear evidence gap.
Return or create:
text<skill-name>/ SKILL.md references/ examples/ scripts/ # optional; include only for deterministic checks or fragile repeated operations evals/ creation-report.md
creation-report.md must follow references/creation-report-template.md and include:
accept, revise, merge_into_existing, split_required, reject, or blocked.experimental, validated, or blocked.Before calling the generated skill ready, compare:
| Arm | Purpose | |---|---| | no_skill | Measures the agent's baseline without the new skill. | | candidate_skill | Measures whether the generated skill changes behavior in the intended direction. | | human_gold | Anchors quality against the original office workflow, SOP, or expert sample when available. |
Use at least 2 selection prompts and 1 behavior prompt for first gate. For high-risk, public, external-send, or multi-agent skills, require 3 to 5 held-out tasks and human review.
Decide:
accept: candidate beats or matches baseline, respects boundaries, and has no overlap risk.revise: candidate is promising but fails a contract, routing, or verification requirement.merge_into_existing: an existing skill should absorb the useful behavior.split_required: the candidate bundles unrelated capabilities.reject: the skill does not improve agent behavior or cannot be verified.blocked: evidence, permissions, or evaluation assets are insufficient.Before finishing:
SKILL.md compact and are resources indexed?Load references/source-mechanics.md when you need the research and code mechanics behind this skill, especially Trace2Skill, EvoSkill, SkillLens, Skill-Schema-V2, SkillOpt, and darwin-skill.
Load references/creation-report-template.md when producing creation-report.md.
Use examples/source-workflow.example.md and examples/generated-skill-review.example.md only when the user needs a concrete example of the expected input or review output shape.
Use evals/test-prompts.json when validating this skill or designing the first gate for a generated skill.
Other measured skills in the registry, with their headline benchmark lift.