Claude Seekho

Agent Skills

A skill is a folder containing SKILL.md (instructions) and optional scripts, templates and reference files. Claude loads a skill only when needed — this gives specialized knowledge without filling the context.

15.1 Progressive disclosure

How much context a skill takes
  1. 1.Level 1: Metadata: name + description — always in context (very small)
  2. 2.Level 2: SKILL.md body: loaded when the task matches the skill
  3. 3.Level 3: Extra files: reference docs, scripts — only when needed; scripts are run, not read

That is why installing many skills does not fill the context

15.2 SKILL.md format

---
name: sql-review
description: Reviews SQL Server queries for performance and security.
  Use when the user shares a SQL query, stored procedure or execution plan.
---

# SQL Review

## Steps
1. Check the query for SELECT *, missing WHERE, implicit conversions.
2. Read `reference/indexing.md` for index suggestions.
3. If there is an execution plan, run `scripts/parse_plan.py`.

## Output
Table: Issue | Severity | Fix

15.3 Where skills run

SurfaceHow
claude.aiEnable/upload skills in Settings; built-in skills (docx, xlsx, pptx, pdf)
Claude Code~/.claude/skills/<name>/SKILL.md (personal) or .claude/skills/ (project); also via plugins
Claude APIIn container.skills with the code execution tool; upload through the Skills API
Agent SDK / Managed AgentsAttach skills in the agent config