- Updated
- Version
- v1.7
- Sources
- 5 sources
- Status
- Published
Agent Skill · SKILL.md
Skill
A versionable directory of instructions and resources that an agent can discover and load to apply a reusable procedure.
Everyday phrases
- a versioned playbook for the agent
- reusable instructions triggered at the right time
Key difference
A skill organizes know-how; it is neither the tool that acts, the agent that chooses, nor a one-off prompt.
Example
A UI audit skill describes its triggers, steps, evidence, and references to load.
Counter-example
A single API request without a decision procedure is not a complete skill.
Continue with a guide
Related concepts
Sources
- https://agentskills.io/specification
- https://agentskills.io/skill-creation/optimizing-descriptions
- https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview
- https://platform.claude.com/docs/en/agents-and-tools/agent-skills/best-practices
- https://learn.chatgpt.com/docs/build-skills
Revision glossary-v1.7:skill · 2026-08-03
- Sourced content digest
- sha256:8ef6df2c4d7e6c39fcf999260288a1940d0b4c8c5b699b75c7dae51c7c7e5e06
Understand → Recognize → Choose → Compare
Pack for your agent
Pre-written instruction by SkillCodex — your request is neither sent nor used to adapt this text; no content is generated, and copying executes nothing.
Implement correctly
Use Skill deliberately
# Ground Skill in your agent ## Objective Use “Skill” precisely in code, documentation, and conversations: A versionable directory of instructions and resources that an agent can discover and load to apply a reusable procedure. ## Prerequisites - Inspect how the term is used today in the repository, documentation, and prompts. - Identify the neighboring notions already named: Prompt, Tool, Model Context Protocol (MCP). - Preserve existing correct usages. ## Working definition A versionable directory of instructions and resources that an agent can discover and load to apply a reusable procedure. ## Decisive difference A skill organizes know-how; it is neither the tool that acts, the agent that chooses, nor a one-off prompt. ## Example that counts as Skill A UI audit skill describes its triggers, steps, evidence, and references to load. ## Counter-example A single API request without a decision procedure is not a complete skill. ## Acceptance criteria - Every use of the term matches the working definition. - Edge cases are settled with the decisive difference, not by intuition. - Neighboring notions (Prompt, Tool, Model Context Protocol (MCP)) are named with their own term. ## Guardrails - Show the proposed changes before any external action. - Do not publish, send, delete, pay for, or change remote state without explicit authorization. - Preserve unrelated changes and stop if the scope becomes ambiguous. ## Output format - Outcome or verdict. - Files or actions involved. - Checks run and observable evidence. - Remaining blockers or limitations.
- Requires · The agentic vocabulary already used in the repository and documentation
Why it works
- The notion is framed by a sourced working definition, not ambient usage.
- The decisive difference settles edge cases reproducibly.
- The example and counter-example bound the term on both sides.
Try next
Map the neighboring notions
# Map the neighboring notions ## Objective Extend the same rigor to the related notions (Prompt, Tool, Model Context Protocol (MCP)) so the project vocabulary stays coherent. ## Checks - List every neighboring notion used without a definition. - Apply its documented decisive difference. - Record the still-ambiguous cases for the next entry. ## Guardrails - Show the proposed changes before any external action. - Do not publish, send, delete, pay for, or change remote state without explicit authorization. - Preserve unrelated changes and stop if the scope becomes ambiguous. ## Output format - Outcome or verdict. - Files or actions involved. - Checks run and observable evidence. - Remaining blockers or limitations.
sha256:e5a42123cc1f73ad61130b4f110f0ae8759d3b96483aeadcff7e813436cfc7d2
Diagnose a problem
Fix a Skill mix-up
# Fix a mix-up around Skill ## Observed symptom [DESCRIBE THE SYMPTOM HERE] ## Observable checks - Compare the disputed usage with the working definition: A versionable directory of instructions and resources that an agent can discover and load to apply a reusable procedure. - Apply the decisive difference: A skill organizes know-how; it is neither the tool that acts, the agent that chooses, nor a one-off prompt. - Confront the case with the documented counter-example: A single API request without a decision procedure is not a complete skill. ## Possible causes - The term is used for a neighboring notion (Prompt, Tool, Model Context Protocol (MCP)). - The observed form (interface, script, service) is confused with the actual behavior. - An alias (Agent Skill, SKILL.md) carries a different meaning in the project. ## Bounded fixes - Rename or reclassify only the usages that contradict the working definition. - Document each choice by citing the decisive difference. ## Final verification - Reread every corrected occurrence against the documented example and counter-example. ## Guardrails - Show the proposed changes before any external action. - Do not publish, send, delete, pay for, or change remote state without explicit authorization. - Preserve unrelated changes and stop if the scope becomes ambiguous. ## Output format - Outcome or verdict. - Files or actions involved. - Checks run and observable evidence. - Remaining blockers or limitations.
- Requires · The agentic vocabulary already used in the repository and documentation
Why it works
- The diagnosis compares usage with documented criteria instead of an opinion.
- Fixes stay bounded to genuinely contradictory usages.
- The final verification runs back through the sourced example and counter-example.
Try next
Anchor the vocabulary in the project
# Anchor the vocabulary in the project ## Objective Turn the clarification into a reusable rule so the mix-up does not return. ## Checks - Add the working definition to the project glossary. - Link every neighboring term to its own entry. - Check new documents against the decisive difference. ## Guardrails - Show the proposed changes before any external action. - Do not publish, send, delete, pay for, or change remote state without explicit authorization. - Preserve unrelated changes and stop if the scope becomes ambiguous. ## Output format - Outcome or verdict. - Files or actions involved. - Checks run and observable evidence. - Remaining blockers or limitations.
sha256:9b527351b153e0f749a8108a28323158bc6957d86cf0379d0389e5160e3aaedb
Pack digest: sha256:7900cf09a6b689b84e09d92d7c849927ec487c70570cdaf34f936521413577bd