> For the complete documentation index, see [llms.txt](https://docs.getlynk.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.getlynk.ai/concepts/skill.md). # Skill A lazy prose procedure for a class of analytical reasoning — root-cause analysis, churn investigation, pipeline review. Skills capture *how the agent thinks*, not *what exists in the data*. ## What it is A skill is the runbook you'd hand a junior analyst for a recurring kind of analysis. It is verb-shaped — "how to investigate churn" — not noun-shaped. That distinction is the rule that keeps `skills/` from becoming a garbage drawer: * A **fact** about an entity goes on the [entity](/concepts/entity.md). * A **way of reasoning** across an analysis goes in a skill. Two further rules follow: * **Skills don't define new schema.** If a skill needs a value the schema doesn't have, add a [feature](/concepts/entity/schema-yml/feature.md) or [metric](/concepts/entity/schema-yml/metric.md) — don't compute it inside the skill. Skills *use* features and metrics; they don't define them. * **Skills don't compose with other skills.** A skill is an encapsulated procedure. It may inject content from entities, glossary terms, or supporting files via `@`, but skills don't merge or extend one another. ## Where it lives A folder per skill inside a [domain](/concepts/domain.md), with optional supporting files alongside the primary file: ``` .lynk/domains//skills// ├── SKILL.md └── examples/ └── enterprise-churn-2024-q3.md ``` **Loaded lazily.** The agent indexes skills by their frontmatter `description` and loads a skill's body only when it's relevant to the question. Skills that don't apply stay unloaded — the brain is large, the agent's working memory is focused. ## Format `SKILL.md` follows the shared [frontmatter contract](/reference/markdown-format.md#frontmatter-contract) — `name` (matching the folder), `description`, optional `enabled` — over a prose body. The `description` is load-bearing: it's what the agent reads at index time to decide relevance. Write it so the agent can tell, from one line, whether a question calls for this skill. The body is whatever helps the agent reason — procedures, decision trees, references to specific entities and metrics. Use the [`@` operator](/reference/markdown-format.md#references) to inject the exact definitions the procedure leans on, so the prose stays focused while the specifics are pulled in at load time. ## Examples **Frontmatter and a short procedure.** ```markdown --- name: pipeline-review description: How to review sales pipeline health — stage coverage, aging, and slippage risk enabled: true --- # Pipeline Review 1. Coverage: compare open pipeline to quota by stage. 2. Aging: flag deals past the median days-in-stage for their stage. 3. Slippage: list deals whose close date moved more than once this quarter. ``` **A churn investigation skill (in the `core` domain) that injects definitions.** The `@` paths stay within `core`, the skill's own domain. ```markdown --- name: churn-investigation description: How to investigate customer churn — identify signals, segment by cohort, surface patterns enabled: true --- # Churn Investigation When investigating churn, start with these signals: 1. Usage decline — see @customer.active_subscription_count.description 2. Pending cancellation — see @subscription.is_pending_cancellation.description 3. Support escalation — see @glossary.at_risk.description Cohort the analysis by signup quarter. The team's working definition of churn is in @glossary.logo_churn.description. For a past investigation: - @/.lynk/domains/core/skills/churn-investigation/examples/enterprise-churn-2024-q3.md ``` ## Validation * `SKILL.md` declares `name` and `description`; `name` matches the folder. * A skill that references an undefined feature or metric fails — skills use schema, they don't define it. ## Related * [Entity](/concepts/entity.md) — where facts live, versus a skill's reasoning * [Feature](/concepts/entity/schema-yml/feature.md) · [Metric](/concepts/entity/schema-yml/metric.md) — what skills use, not define * [Policy](/concepts/policy.md) — *how to operate*, versus a skill's *how to reason* * [Markdown format](/reference/markdown-format.md) — the frontmatter contract and `@` operator * Guides: [Placing knowledge in a layer](/guides/where-knowledge-goes.md) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.getlynk.ai/concepts/skill.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. 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