Curating Library Kg Agent Skill

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

• 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.
• Custom descriptions for "high" quality blocks are encouraged but optional.
• Write custom descriptions for as many blocks as possible. After covering low/medium, covering high blocks too improves the KG.
• Process in batches by category. Group blocks, infer descriptions together, present to user in digestible chunks.
• 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.

• Review (only if KG exists) — Read index.md and common.md, summarize current state to user (libraries, block count, categories, common blocks).
• Mode selection — Determine Automatic or Guided. Do not proceed without completing this step.
• 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.
• Common blocks — Propose which blocks should be marked as commonly used. Consider blocks covering diverse categories and frequent modeling workflows. Save to commonBlocks.
• Categories — Finalize category definitions (names, descriptions, 3-5 keywords each). Allow user to correct individual block assignments via categoryAssignments.
• 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%.
• 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

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

Reading block metadata

Read .satk/library-cache/*.json directly. Each file:

{
  "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

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

{
  "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.

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Copyright 2026 The MathWorks, Inc.

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