Glossary
49 terms from “Claude Code Skills: Build Your Own AI Workflows.” Hover the first occurrence in the lesson for its definition.
| Term | Definition | Source |
|---|---|---|
| Skill | A directory plus a SKILL.md file: a reusable package of workflow instructions that tells Claude how to do one specific task. | Anthropic engineering blog: Equipping agents for the real world with Agent Skills |
| SKILL.md | The core file of a Skill, containing two parts: YAML frontmatter (metadata) and Markdown instructions (the directions Claude follows). | Claude Code official docs: Extend Claude Code with skills |
| YAML frontmatter | The metadata block at the top of SKILL.md, wrapped in triple-dash (---) markers, holding fields like name and description. | Claude Code official docs: Extend Claude Code with skills |
| name | A required frontmatter field that defines the Skill's unique identifier; it becomes the command and must use lowercase letters, digits, and hyphens. | Anthropic engineering blog: Equipping agents for the real world with Agent Skills |
| description | A required frontmatter field that tells Claude what the Skill does and when to use it. It is the sole basis for automatic triggering. | Building skills for Claude, hands-on: YAML frontmatter and testing |
| automatic triggering | When what the user says matches a Skill's description, Claude loads and runs that Skill on its own, with no manual command. | Building skills for Claude, hands-on: YAML frontmatter and testing |
| manual invocation | Calling a Skill directly with /skill-name, which forces Claude to load it without relying on the description matching. | Claude Code official docs: Extend Claude Code with skills |
| Markdown instructions | Everything in SKILL.md after the frontmatter: the concrete, step-by-step directions Claude follows, written in Markdown. | Claude Code official docs: Extend Claude Code with skills |
| progressive disclosure | Giving Claude only what it needs right now instead of dumping every detail at once, so the Skill stays short and loads fast. | Anthropic platform docs: Agent Skills overview |
| supporting files | Files in a Skill directory other than SKILL.md (checklists, config, scripts) that are loaded on demand and don't consume initial context. | Anthropic platform docs: Agent Skills overview |
| personal skills | Skills stored in ~/.claude/skills/, available only to you but usable across every project. Good for personal habits and general-purpose tools. | Teach Claude Code your workflow: a hands-on guide to custom skills |
| project skills | Skills stored in a project's .claude/skills/ directory, committed to Git so teammates get them automatically when they clone the repo. | Teach Claude Code your workflow: a hands-on guide to custom skills |
| Repetition | One of the three traits that make a scenario suit a Skill: you do the same thing daily, weekly, sometimes hourly. | Claude Code official docs: Extend Claude Code with skills |
| Fixed steps | One of the three traits that make a scenario suit a Skill: the process can be written as clear steps rather than changing every time. | Claude Code official docs: Extend Claude Code with skills |
| Verifiable | One of the three traits that make a scenario suit a Skill: you can tell whether Claude got the result right. | Claude Code official docs: Extend Claude Code with skills |
| description formula | The guideline for writing an effective description: what it does + when to use it + key capabilities. | Building skills for Claude, hands-on: YAML frontmatter and testing |
| trigger keywords | The words in a description that a user might plausibly say; Claude matches on these to decide whether to auto-load the Skill. | Building skills for Claude, hands-on: YAML frontmatter and testing |
| Input Format | The instructions section that spells out what kind of input the Skill accepts, including shape, source, and a concrete example. | Claude Code official docs: Extend Claude Code with skills |
| Processing Steps | The ordered, concrete operations the Skill runs; the heart of the instructions, where each step should be specific enough to be unambiguous. | Claude Code official docs: Extend Claude Code with skills |
| Output Format | The instructions section defining what the result should look like, including structure, symbols, and a worked example. | Claude Code official docs: Extend Claude Code with skills |
| edge cases | Unusual or abnormal inputs (empty input, malformed input, over-long content) whose handling must be spelled out explicitly in the instructions. | Claude Code official docs: Extend Claude Code with skills |
| direct invocation | The simplest test: call the Skill with /skill-name and watch whether the output matches expectations. | Claude Code official docs: Extend Claude Code with skills |
| test cases | Prepared input-and-expected-output pairs used to test a Skill systematically before relying on it. | Claude Code official docs: Extend Claude Code with skills |
| iteration loop | The test-find-fix-retest cycle a Skill goes through; the path from 'it runs' to 'it runs well.' | Claude Code skills: .NET workflows and reusable prompts |
| A/B it | Running the same task with and without the Skill and timing both, to prove whether the Skill is actually faster and more consistent. | Claude Code skills: .NET workflows and reusable prompts |
| checklist pattern | Organizing a complex task as a series of explicit check items, each of which can independently pass or fail. | Claude Code official docs: Extend Claude Code with skills |
| multi-step workflow | A Skill that runs several sequential steps to finish a complex task, where one step's output may feed the next. | Claude Code official docs: Extend Claude Code with skills |
| Grading the output | Splitting a Skill's findings by severity (passed, worth a look, must fix) so the reader knows what to act on first. | Claude Code official docs: Extend Claude Code with skills |
| version control | Managing project skills with Git so you can view history, roll back, and compare versions, the same way you manage code. | Claude Code skills: .NET workflows and reusable prompts |
| Reviewing a Skill | Reviewing a new or changed Skill the way you review code: check the description, the instructions, and the tests before merging. | Claude skills as self-documenting runbooks |
| naming convention | A team-wide, agreed-on style for Skill names: hyphens, verb-noun or noun-verb order, two or three words. | Claude Code skills: .NET workflows and reusable prompts |
| prune on a schedule | Reviewing all Skills once a quarter and deleting or improving the ones that barely get used, so an unused pile doesn't crowd Claude's choices. | Claude Code skills: .NET workflows and reusable prompts |
| announce changes | After changing an existing Skill, post the change and its impact in the team channel so people don't operate the new Skill on old assumptions. | Claude Code official docs: Extend Claude Code with skills |
| Composing Skills | Chaining several single-purpose Skills to handle one larger task, or referencing one Skill from inside another. | Anthropic engineering blog: Equipping agents for the real world with Agent Skills |
| allowed-tools | An optional frontmatter field that restricts a Skill to a specified set of tools, drawing a permission boundary for security-sensitive cases. | Claude Skills deep dive (a first-principles view) |
| disable-model-invocation | An optional frontmatter field that, when set, stops Claude from auto-loading the Skill, leaving manual invocation only, to avoid accidental triggers. | Claude Skills deep dive (a first-principles view) |
| model | An optional frontmatter field that pins a specific model for the Skill, for example a stronger reasoning model when the task needs it. | Claude Skills deep dive (a first-principles view) |
| MCP server | A Model Context Protocol server that supplies tools (database access, API calls) to Claude; a Skill supplies the workflow knowledge for using them. | The complete guide to building skills for Claude (PDF) |
| Community Skills | Skills built and shared by other developers, findable on GitHub and elsewhere. | Claude Code official docs: Extend Claude Code with skills |
| Documenting Skills | Listing every project skill, with usage and examples, in the project README or .claude/README.md. | Claude skills as self-documenting runbooks |
| single responsibility | Each Skill should do one thing and do it well, rather than trying to solve several unrelated problems in one Skill. | Anthropic engineering blog: Equipping agents for the real world with Agent Skills |
| context | When Claude loads a Skill, the SKILL.md content occupies the context window; the longer the file, the more it consumes. | Anthropic platform docs: Agent Skills overview |
| loaded on demand | Supporting-file content is read only when Claude actually needs it, so it doesn't occupy context at the Skill's initial load. | Anthropic platform docs: Agent Skills overview |
| false positives | When a Skill flags normal code or content as a problem; fix it by adding a 'needs confirmation' category or tuning the criteria. | Claude Code official docs: Extend Claude Code with skills |
| Misses | When a Skill fails to catch a problem it should have found; fix it by adding check rules or adjusting the judgment logic. | Claude Code official docs: Extend Claude Code with skills |
| loading-failure | When a Skill won't auto-load or a manual call fails, the diagnostic process of checking file path, frontmatter format, and name spelling in that order. | Claude Code official docs: Extend Claude Code with skills |
| Examples | Providing input/output examples so Claude understands the expected behavior; a worked example does more than prose description. | Claude Code official docs: Extend Claude Code with skills |
| feature branch | Creating or changing an experimental Skill on a Git branch and merging to main only once it earns it, so the team isn't disrupted. | Claude Code official docs: Extend Claude Code with skills |
| workflow knowledge | Knowledge about how to organize steps, when to use which tool, and how to judge the result; the core value a Skill supplies. | The complete guide to building skills for Claude (PDF) |