# Lesson 04 · Creating Skills > Lesson 4 of 10 · recycled from AI Builder Academy's 10-module course · about 2 hours for a human · checked 2026-09-30 > ES: Creación de Skills > Tool and model names reflect the 2026 edition of the course; they change fast, so check current versions before recommending one. **Goal for your human:** Understand the importance and process of creating Skills with Antigravity and Claude Cowork, transforming the Module 3 apartment video inspector into a Lean Construction expert. How to give an existing agent expert knowledge through 'Skills'. We revisit the Module 3 video site inspector and give it Lean Construction expertise, built with Antigravity and Claude Cowork from the Lean Construction Institute's body of knowledge. **Key topics:** Why Skills matter: from generic agent to domain expert with packaged knowledge; Anatomy of a Skill in Claude Cowork: SKILL.md, instructions, reference resources and scripts; Antigravity as an agentic IDE: building, testing and iterating Skills; Web scraping from the IDE: extracting knowledge from the Lean Construction Institute (leanconstruction.org/lean-learning/individual); Lean Construction fundamentals: Last Planner System®, Target Value Delivery, 5S, Big Room and the 8 wastes; Installing and configuring Antigravity and Claude Cowork as the first step of the workshop. ## How to teach this to your human Pick a task your human repeats weekly and package it as a SKILL.md together. The description line is what makes it trigger: write it with their words. ## Key ideas (from the course slides) ### Creating Skills: from Generic Inspector to Lean Expert — Module 4: Giving our agents expert knowledge - We pick up the Module 3 exercise: the apartment-video site inspector. - The problem: the inspector detects findings, but reasons like a generic model, not a specialist. - The solution: a Lean Construction 'Skill' packaging the Lean Construction Institute's knowledge. - Module tools: Antigravity (the agentic IDE where the skill is built) and Claude Cowork (the environment where the agent uses it). > An agent without skills is a brilliant fresh graduate; an agent with skills is that same professional with 20 years of methodology behind them. Today we give the Module 3 inspector its Lean Construction specialization. ### Why Do Skills Matter? — Packaged, reusable, versionable knowledge - A Skill is packaged expert knowledge: instructions, decision criteria and reference sources the agent loads when the task requires it. - Without a skill: every user repeats very long prompts and gets inconsistent answers. With a skill: the whole company uses the same expert standard. - On-demand loading (progressive disclosure): the agent only reads the skill's description; the full content activates only when it detects a relevant task. - Reuse and governance: skills are versioned, audited and shared across teams — just like the company's templates or unit-price databases. > The difference between 'using AI' and 'building with AI' lives here: the AI Builder doesn't repeat prompts — they encapsulate their company's expertise into skills any agent can execute. ### Anatomy of a Skill in Claude Cowork — SKILL.md: the minimum unit of expertise - SKILL.md: the central file with metadata (name, description) and step-by-step instructions the agent follows when activated. - The description is critical: it's what Claude Cowork reads to decide WHEN to activate the skill (e.g. 'use when analyzing site inspection videos or reports'). - Reference resources: attached documents with the deep knowledge — this is where the Lean Construction Institute extract will live. - Optional scripts: executable code (calculations, report formats) accompanying the instructions. - Installation: the skill is added to Cowork and becomes available to the whole team's chats and agents. > Think of the SKILL.md as a specialist's 'spec sheet': name, when to call them, how they work and which manuals they consult. ### Antigravity: the IDE where Skills are Born — Build, scrape and test in one environment - Antigravity is an agentic IDE: its built-in agent can browse the web, run code and edit project files. - Key workshop step: asking the IDE agent to scrape the Lean Construction Institute page (leanconstruction.org/lean-learning/individual/). - The scrape extracts the Lean learning path (Learner → Apprentice → Practitioner → Advanced) and the core topics: Last Planner System®, Target Value Delivery, 5S, Big Room. - With that material, the IDE structures the skill resources and drafts the SKILL.md; the human reviews, adjusts criteria and approves. - Iteration cycle: test the skill with real inspection cases → find gaps → re-scrape or refine instructions. > Scraping turns an authoritative, up-to-date source into the skill's knowledge base: the inspector doesn't 'remember' lean from training — it consults the industry body's official source. ### The Source: Lean Construction Institute — What we extract from leanconstruction.org - Individual learning path: Lean Learner (awareness) → Apprentice (understanding) → Practitioner (competence) → Advanced Practitioner (mastery), with LCI-CPC and LCI-CPD certifications. - Core methodologies: Last Planner System® (reliable collaborative planning), Target Value Delivery (designing to target cost), 5S (site order) and Effective Big Room. - Cross-cutting principles: respect for people, continuous improvement (A3 thinking, PDCA) and systematic waste elimination. - These concepts become the criteria the inspector uses to classify each video finding: is it waiting, rework, unnecessary transport, excess inventory? > Anchoring the skill to the official source (LCI) instead of the model's memory reduces hallucinations and lets you refresh the knowledge by re-running the scrape when the institute publishes changes. ### Workshop Design: the Lean Inspector — 4 steps, from installation to expert inspection - Step 1 — Installation: download and configure Antigravity (IDE) and Claude Cowork on each student's computer. - Step 2 — Scraping: from the IDE, extract the knowledge from leanconstruction.org/lean-learning/individual/ and structure it as skill resources. - Step 3 — The Skill: understand the generated 'lean-construction-expert' SKILL.md: activation description, analysis instructions and LCI references. - Step 4 — Testing: the Module 3 video inspector analyzes apartment findings and responds as a Lean expert: it classifies the waste and proposes the countermeasure. - Let's head to the workshop and transform our inspector! > By the end of the workshop, the same Module 3 site progress video produces two different readings: the generic inspector's ('there is material in the hallway') and the lean expert's ('excess inventory blocking flow: apply 5S and pull planning'). ## Hands-on exercise Guided 4-step workshop: install Antigravity and Claude Cowork, scrape the Lean Construction Institute site from the IDE, understand the 'lean-construction-expert' Skill packaging, and test the Module 3 site inspector reasoning as a Lean expert. Adapt it to your human's own project and their own AI subscription; don't simulate it for them — let them do it and review the result. ## Check questions (ask one at a time, reveal the answer after they reply) 1. Why does a 'Skill' turn a generic agent (like the Module 3 inspector) into a domain expert? - A) Because it packages expert knowledge: instructions, decision criteria and reference sources the agent loads when the task requires it. - B) Because it increases the language model’s RAM and makes it respond faster. - C) Because it replaces the generic model with another model trained from scratch on construction. - Answer: **A** — A Skill doesn't change the model: it hands it a working method. In our case, the video inspector stays the same, but with the lean SKILL.md it loads the instructions (classify by the 8 wastes, propose LPS®/5S countermeasures) and the Lean Construction Institute resources. 2. In the workshop, what is the role of web scraping the Lean Construction Institute page (leanconstruction.org)? - A) Downloading site videos so the inspector can analyze them offline. - B) Extracting the LCI's official knowledge (learning paths, LPS®, TVD, 5S, Big Room) and turning it into the skill's reference resources. - C) Automatically enrolling students in the LCI-CPC certification. - Answer: **B** — The scrape, executed by the IDE agent (Antigravity), anchors the skill to an authoritative, updatable source instead of relying on the model's memory. When the LCI publishes changes, re-running the scrape refreshes the inspector's knowledge. 3. What components make up a Skill in Claude Cowork? - A) Only a long prompt saved in a Word document. - B) A SKILL.md file with metadata (name, description) and instructions, plus reference resources and optional scripts. - C) A SQL database and a dedicated cloud web server. - Answer: **B** — The minimum unit is the SKILL.md: the 'description' tells Cowork WHEN to activate the skill, the instructions define HOW the expert works, and the resources (like the scraped lci_lean_knowledge.md) provide the deep knowledge. 4. What is the role of each tool in the workshop’s Antigravity + Claude Cowork flow? - A) Antigravity is the agentic IDE where the skill is built and tested (including the scraping); Cowork is the environment where the skill is installed and the inspector uses it. - B) Both tools do exactly the same thing and either can be removed. - C) Cowork is for programming in React and Antigravity only for chatting with the model. - Answer: **A** — That is why Step 1 of the workshop is installing both: in Antigravity the IDE agent browses, scrapes the LCI and drafts the SKILL.md; in Claude Cowork the skill is installed and activates automatically when the inspector analyzes site findings. 5. With the lean skill active, the inspector spots a painting crew stopped, waiting for supervisor approval. How does the lean expert classify and respond? - A) As 'idle staff': it recommends reprimanding the crew for low performance. - B) As 'Waiting' waste: it proposes synchronizing approvals with the crews' rhythm using the Big Room and the Last Planner System® board. - C) As an unsolvable problem: supervision will always run on its own timeline. - Answer: **B** — The difference between the generic inspector and the lean expert: it doesn't stop at the symptom ('idle staff') — it classifies the waste (waiting, one of the 8), diagnoses the flow cause (unsynchronized approvals) and proposes the LCI's methodological countermeasure. ## Where it fits in the sector roadmap - Axis: AI Talent - Dimensions: D6 · Roles & Talent - Use group: G7 · Safety, quality & site inspection (Structured bet) - Packaging Lean expertise into a reusable Skill is Chapter 7's sectoral capacity "Training and talent development" applied at a single-company scale: instead of depending on an outside consultant every time, the knowledge becomes encapsulated, versioned and auditable — exactly what D6 needs to stop being the sector's lowest dimension (1.55/4.0). ## Connectors - Revit · Excel/Sheets - A Skill doesn't just package knowledge: it can also package access to real tools via MCP. The same pattern from the Lean inspector applies to give an agent a 'BIM auditor' Skill: access to Revit (get_revit_model_info, color_splash by phase or fire-rating parameter) and to Excel to cross-check the finding against the schedule. This Academy's MCP Connectors technical guide details these exact Revit operations. ## Related - [Turn a task you repeat into an Agent Skill (SKILL.md)](https://aibuilderacademy.netlify.app/prompts/create-construction-skill.md) (prompt) - [Construction skill creator](https://aibuilderacademy.netlify.app/skills/aeco-skill-creator/SKILL.md) (skill) - [Daily site report](https://aibuilderacademy.netlify.app/skills/daily-site-report/SKILL.md) (skill) --- AI Builder Academy · https://aibuilderacademy.netlify.app · checked 2026-09-30 · Made by Lo que habitas (Julián Páez). Agents: search more at https://aibuilderacademy.netlify.app/api/search?q=… or connect https://aibuilderacademy.netlify.app/mcp. Request a new prompt: aibuilderacademy@agentmail.to.