Skill Load Tips

Skill Load Tips

Refactor pattern for SKILL.md files where the body is the only thing the agent ever reads. The references/ folder might as well not exist.

The Failure Mode

Large skills frequently ship with rich reference files (references/*.md) that contain the load-bearing detail — full ARIA patterns, banned-vocab lists, before/after examples, archetypes — and a SKILL.md body that summarizes them. The agent reads the body, feels it has "enough," and never fans out. The reference files become dead weight.

This is the inline-substitutes-for-reference antipattern. It is the single most common reason a well-organized skill underperforms.

Symptoms (how to spot it)

A SKILL.md likely has this problem if two or more apply:

• Body is over 250 lines and inlines checklists, tables, or banned-word lists that also live in a referenced file.
• The "Reference Index" / "Files" section is at the bottom, after the operating loop.
• References are introduced with hedged phrases: "For depth, read X", "see X for details", "X has more".
• No upfront "router" mapping task → mandatory file.
• Reference files are linked from other reference files (deep nesting), not directly from SKILL.md.
• Reference files over 100 lines have no table of contents at the top.

The Four Fixes (apply in order)

Fix 1 — Add a Required Reading Router at the top

Insert a table immediately after the skill's opening paragraph (before any "Operating Loop" / "Steps" section). The table maps task type → file(s) that MUST be read for that task.

Template:

## Required Reading Router

Match your task to the row. Read the listed files **in full before** producing output. They are not appendices — they are load-bearing. Inline content in this SKILL.md is a pointer, not a substitute.

| Task                                          | MUST read                                                    |
| --------------------------------------------- | ------------------------------------------------------------ |
| [Task type A]                                 | `references/file-a.md`                                       |
| [Task type B]                                 | `references/file-b.md` + `references/file-c.md`              |
| [Task type C]                                 | `references/file-d.md`                                       |

Pair the router with a Reference Index directly below it: one-line descriptions of what each file contains, so the router tells the agent when to load and the index tells what they get.

Fix 2 — Use hard STOP directives in operating steps

Every step that has a corresponding reference file gets a forced-read directive at the end. Replace soft phrasing with imperative.

Before:

For ARIA component patterns and verification recipes, read `references/accessibility-floor.md`.

After:

**STOP. Read `references/accessibility-floor.md` in full before implementing or reviewing any interactive widget.** That file contains the complete ARIA patterns (dialog, combobox, menu, tabs, slider, listbox) and the verification recipes. The inline summary above is a tripwire, not the contract.

Three rules for STOP directives:

1. Bold the word STOP. It is a visual interrupt.
2. Name the trigger condition ("when implementing an interactive widget", "when extending tokens"). Not just "if you want depth."
3. State that the inline content is a tripwire, not the source of truth.

Fix 3 — Trim duplicated inline content to gist tripwires

When a SKILL.md step contains a 10-bullet checklist that is also in a reference file, the agent reads the checklist and skips the reference. Cut the inline to a 2-3 line "tripwire" — enough for the agent to detect violations during scanning, but obviously incomplete.

Before (inline 10-bullet WCAG checklist):

- Text contrast ≥ 4.5:1 (≥ 3:1 for large text)
- Non-text indicators contrast ≥ 3:1
- Focus visible (2px minimum)
- Keyboard reachable
- Target size ≥ 24×24
- prefers-reduced-motion honored
- Semantic landmarks
- Headings in order
- Form controls labeled
- Errors associated via aria-describedby

After (3-line tripwire + forced read):

Gist tripwires — the floor items that catch most slop:

- Text contrast ≥ 4.5:1; focus-visible ≥ 2px on every interactive element.
- Full keyboard reachability; `prefers-reduced-motion` honored.
- Semantic landmarks + heading order; form controls programmatically labeled.

**STOP. Read `references/accessibility-floor.md` in full before implementing or reviewing any interactive widget.** The three bullets above are tripwires, not the contract.

Trim aggressively. If the inline list and the reference cover the same ground, the reference always wins.

Fix 4 — Flatten reference depth to one level

Per Anthropic's docs: when references link to references, the agent uses partial reads (head -100) and misses content. All references/*.md files must be linked directly from SKILL.md, not from each other.

Bad:

SKILL.md → references/advanced.md → references/details.md

Good:

SKILL.md → references/advanced.md
SKILL.md → references/details.md

Also: any reference file over 100 lines needs a ## Contents section at the top, so partial reads still surface the scope.

Anti-Patterns

Things that look like fixes but aren't:

• Adding "(important)" or emoji to existing trigger lines. The agent reads tone, not decoration. Mandatory phrasing requires verbs (STOP. Read…), not adjectives.
• Making references shorter so the body can stay inline. The opposite of the goal. References should grow as the body shrinks.
• Adding a "TL;DR" at the top of every reference file. The agent reads the TL;DR and skips the body. Use a Contents TOC instead — names of sections, not summaries.
• Renaming references to suggest urgency (URGENT-read-this.md, MUST-READ.md). The filename does not change the read decision; the trigger phrasing in SKILL.md does.
• Splitting SKILL.md into many small files at the same level. SKILL.md is the single entry point. Multiple top-level skill files break discovery.

Refactor Checklist

Before declaring a refactor done, verify against the rewritten SKILL.md:

• Required Reading Router exists in the first 50 lines (after intro/philosophy).
• Reference Index sits next to the Router.
• Every operating step that has a corresponding reference file ends with a **STOP. Read references/X.md …** directive.
• Inline checklists that duplicate reference content have been trimmed to ≤ 3 bullets, labeled as "tripwires" or "gist."
• No reference file links to another reference file (one level deep only).
• Reference files > 100 lines have a ## Contents TOC at the top.
• SKILL.md body is under 500 lines (Anthropic's recommended ceiling).
• No For depth, see X or Read X for more phrasing remains — every reference mention is either router/index (descriptive) or a STOP directive (mandatory).

How To Run a Refactor Pass

1. Open SKILL.md and the references/ directory side by side.
2. Inventory: list every reference file and what it covers.
3. Diagnose: walk the Symptoms list above; mark each hit.
4. Apply Fix 1 (Router + Index), then Fix 2 (STOPs), then Fix 3 (trim inline), then Fix 4 (flatten depth + add TOCs).
5. Run the checklist. If any item is unchecked, the refactor is not done.
6. Test by asking a fresh agent instance to perform a task that requires a reference file. Observe whether it actually reads the file. If it doesn't, the STOP directive for that file is too weak — strengthen the trigger condition.

When NOT To Use

• Authoring a new skill from scratch — use skill-best-practices.
• Editing reference files themselves without touching SKILL.md.
• Skills under 150 lines with no reference files (nothing to route).
• AGENTS.md / CLAUDE.md refactors — those follow different rules; use agent-md-refactor.

Bottom Line

A reference file the agent never loads is a reference file that does not exist.
The body of SKILL.md is a dispatcher, not an encyclopedia.
Trim the inline. Force the load. Flatten the depth.