---
name: Curating Library Knowledge Index
slug: curating-library-knowledge-index
category: AI Engineering
description: Curating Library Knowledge Index guides the review and editing of library block metadata for agent selection. It is used to assign categories, mark common blocks, and write intent-focused descriptions for low- and medium-quality blocks.
github: "https://github.com/matlab/simulink-agentic-toolkit/tree/main/skills-catalog/model-based-design-core/curating-library-kg"
language: HTML
stars: 963
forks: 94
install: "npx degit https://github.com/matlab/simulink-agentic-toolkit/tree/main/skills-catalog/model-based-design-core/curating-library-kg ~/.claude/skills/curating-library-kg"
installs_to: ~/.claude/skills/curating-library-kg
source_path: skills-catalog/model-based-design-core/curating-library-kg/SKILL.md
collection_size: 24
category_size: 2451
collection_url: "https://dirskills.com/collections/matlab/simulink-agentic-toolkit"
added: 2026-08-21T05:15:11.430Z
last_synced: 2026-08-21T05:15:11.430Z
canonical_url: "https://dirskills.com/skills/curating-library-knowledge-index"
---

# Curating Library Knowledge Index

Curating Library Knowledge Index guides the review and editing of library block metadata for agent selection. It is used to assign categories, mark common blocks, and write intent-focused descriptions for low- and medium-quality blocks.

**Install:**

```bash
npx degit https://github.com/matlab/simulink-agentic-toolkit/tree/main/skills-catalog/model-based-design-core/curating-library-kg ~/.claude/skills/curating-library-kg
```

## README

# Curating the Library Knowledge Index

Curate `.satk/library-kg/` for better agent block selection. Infer categories and descriptions from block metadata in `.satk/library-cache/*.json`, save curation to `.satk/library-curation.json`, then regenerate the KG.

## When to Use

- User wants to mark blocks as commonly used or important
- User wants to correct auto-assigned categories
- User wants to improve block descriptions for better selection
- User asks "how do I make the agent prefer certain blocks?"
- Called from `building-simulink-models` Gate 3.

## When NOT to Use

- Blocking, deprecating, or protecting blocks → `configuring-block-policy`
- Actively building a model → `building-simulink-models`
- Declaring which libraries exist → Library Setup gate in `building-simulink-models`

## Prerequisites

- `satk-libraries.json` or  `.satk/reuse-libraries.json`  must exist with libraries declared

## Curation Rules

1. **Custom descriptions are mandatory for ALL `metadataQuality: "low"` and `"medium"` blocks across ALL declared libraries.** These blocks have no useful information. Write a short intent-focused description for every such block to help with agent block selection. Do not skip blocks because a file is large or because they seem unrelated to the current task.
2. **Custom descriptions for `"high"` quality blocks are encouraged but optional.** 
3. **Write custom descriptions for as many blocks as possible.** After covering low/medium, covering high blocks too improves the KG.
4. **Process in batches by category.** Group blocks, infer descriptions together, present to user in digestible chunks.
5. **Never write template or mechanical descriptions.** Descriptions like "Mathematical operation: gain" or "Signal routing utility: mux" are useless — they just restate the category and name. Every description MUST be thoughtful, intent-focused description explaining *when* to use the block and *what modeling problem* it solves (e.g., "Scale a signal by a constant factor — use for unit conversion, controller gains, or applying physical constants" instead of "Mathematical operation: gain").

## Modes

- **Automatic** (from Gate 3 "Automatic" option) — infer everything, commit without pausing per step, present final result for review.
- **Guided** (from Gate 3 "Guided setup" or direct user invocation) — propose at each step, wait for user confirmation before proceeding.

Determine mode before starting. Do not proceed without mode selection.

## Workflow

If `.satk/library-kg/index.md` already exists, start at step 1 (review existing state). If not, start at step 2.

1. **Review** (only if KG exists) — Read `index.md` and `common.md`, summarize current state to user (libraries, block count, categories, common blocks).
2. **Mode selection** — Determine Automatic or Guided. Do not proceed without completing this step.
3. **Descriptions** — Ensure cache exists (see API), then read ALL `.satk/library-cache/*.json` files **in full**. If a file exceeds read limits, read it in chunks until every block has been processed. Apply Curation Rules above — write custom descriptions for blocks, prioritizing low/medium quality. Do NOT proceed to Step 4 until descriptions exist for every low/medium quality block across ALL cache files. Save to `customDescriptions`.
4. **Common blocks** — Propose which blocks should be marked as commonly used. Consider blocks covering diverse categories and frequent modeling workflows. Save to `commonBlocks`.
5. **Categories** — Finalize category definitions (names, descriptions, 3-5 keywords each). Allow user to correct individual block assignments via `categoryAssignments`.
6. **Completeness check** — Before saving, count total low/medium quality blocks across ALL cache files and count how many have custom descriptions. Report coverage to the user (e.g., "275/275 low/medium blocks described, 120/285 high blocks described"). Do NOT proceed if coverage of low/medium blocks is below 100%.
7. **Save and generate** — Save all curation data via `library.LibraryCuration.save(projectRoot, curation)`, then run `library.kg.Populate.run(projectRoot)`. Present the output summary to the user.

## API

### Ensuring cache exists

```matlab
libConfig = library.LibraryConfig.load(projectRoot);
library.LibraryCatalog.getOrCreate(libConfig, projectRoot);
```

### Reading block metadata

Read `.satk/library-cache/*.json` directly. Each file:
```json
{
  "libraryName": "MotorLib",
  "description": "Motor control library",
  "blocks": [
    {
      "name": "SpeedController",
      "maskType": "SpeedCtrl",
      "blockType": "SubSystem",
      "maskDescription": "Closed-loop speed regulation with anti-windup",
      "description": "",
      "pathCategory": "Controllers",
      "metadataQuality": "high",
      "referenceBlock": "MotorLib/Controllers/SpeedController"
    }
  ]
}
```

### Saving curation data

```matlab
projectRoot = prefdir();
curation = library.LibraryCuration.load(projectRoot);
curation.commonBlocks = {'Speed Controller', 'Torque Estimator'};
curation.categories = struct('name', 'motors', 'description', 'Electric motors', 'keywords', {{'motor', 'drive'}});

% Use containers.Map — supports any block name as key
curation.customDescriptions = containers.Map('KeyType', 'char', 'ValueType', 'char');
curation.customDescriptions('Unit Delay') = 'Delay signal by one sample period';
curation.customDescriptions('1-D Lookup Table') = 'Interpolate output from breakpoint-value pairs';

curation.categoryAssignments = containers.Map('KeyType', 'char', 'ValueType', 'char');
curation.categoryAssignments('DC Current Controller') = 'motor-control';

library.LibraryCuration.save(projectRoot, curation);
library.kg.Populate.run(projectRoot);
```

**Important:** Use `containers.Map` (not struct) for `customDescriptions` and `categoryAssignments`. Struct field names cannot contain spaces or hyphens, which most Simulink block names have.

### JSON format on disk

```json
{
  "customDescriptions": [
    {"block": "Unit Delay", "value": "Delay signal by one sample period"},
    {"block": "1-D Lookup Table", "value": "Interpolate output from breakpoint-value pairs"}
  ],
  "categoryAssignments": [
    {"block": "DC Current Controller", "value": "motor-control"}
  ]
}
```

## Curation Fields

| Field | Type | Effect |
|-------|------|--------|
| `commonBlocks` | cell array of strings | Always shown in `common.md` regardless of quality score |
| `categories` | struct array with `.name`, `.description`, `.keywords` | Defines categories with keyword matching for assignment |
| `categoryAssignments` | `containers.Map` (blockName → categoryName) | Per-block category assignment |
| `customDescriptions` | `containers.Map` (blockName → description) | Per-block custom description (intent) |

## Guardrails

- **Never call `find_system`, `get_param` on library `.slx` files.** Read `.satk/library-cache/*.json` for metadata, use `library.kg.Populate.run()` to generate the KG, and `library.kg.Query.search()` for lookups.
- Never modify `.satk/library-cache/*.json` or `.satk/library-kg/*.md` directly — they are auto-generated.
- Persist curation via `library.LibraryCuration.save()` only.
- Confirm changes with the user before saving.
- In user-facing output, do not use the term 'override'. Use 'custom description' or 'category assignment' instead.
anges with the user before saving
- For progress tracking during curation, do not mention the term 'override' in user-facing output. Use 'custom description' or 'category assignment' instead.

----

Copyright 2026 The MathWorks, Inc.

----