Agentic Image Alt Text
Generate and set descriptive alt text on product images so AI agents (which can't 'see' pixels) can understand and recommend what each product looks like.
shopify-admin-agentic-image-alt-text
Purpose
An AI shopping agent reads image alt text to understand a product's appearance — color, material, style, use. Blank or filename-style alt text ("IMG_2931.jpg") tells the agent nothing, so it can't match the product to a visual query ("red linen midi dress") or describe it to a shopper. This skill finds product images with missing or low-value alt text and writes concise, descriptive alt text derived from the product's title, options, type, and tags. Fixes the agentiq.report finding listing-image-alt-text.
Prerequisites
shopify auth login --store )read_products, write_products, write_filesParameters
All skills accept these universal parameters:
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| store | string | yes | — | Store domain (e.g., mystore.myshopify.com) |
| format | string | no | human | Output format: human (default) or json |
| dry_run | bool | no | false | Preview mutations without executing |
Skill-specific parameters:
| Parameter | Type | Required | Default | Description |
|---|---|---|---|---|
| collection_id | string | no | — | Limit to a collection GID |
| tag | string | no | — | Limit to a product tag |
| overwrite | bool | no | false | If true, also rewrite filename-style / placeholder alt text; if false, only fill blanks |
| max_chars | int | no | 125 | Alt-text length cap (accessibility + agent-readability) |
Safety
> ⚠️ Step 3 (fileUpdate) writes alt text to live media. With overwrite: true it replaces existing alt text, which is not bulk-reversible. Run dry_run: true first and review the proposed alt text per image. Default (overwrite: false) only fills blanks and is low-risk.
Workflow Steps
products — query Inputs: first: 250, optional collection/tag filter; fields title, productType, tags, options, media{ MediaImage{ id image{ altText } } }; paginate until done.
Expected output: Product media with current alt text + the product context needed to generate good alt text.
overwrite, placeholder) alt text, compose alt text from title + relevant option values (color/material/style) + product type, trimmed to max_chars. Emit a preview table (image id → proposed alt).fileUpdate — mutation Inputs: files: [{ id: in batches (≤ 25).
Expected output: Updated files; collect userErrors.
GraphQL Operations
# products:query — validated against api_version 2025-01
query AltTextProducts($first: Int!, $after: String, $query: String) {
products(first: $first, after: $after, query: $query) {
edges {
node {
id
title
productType
tags
options { name values }
media(first: 20) {
edges {
node { ... on MediaImage { id image { altText url } } }
}
}
}
}
pageInfo { hasNextPage endCursor }
}
}
# fileUpdate:mutation — validated against api_version 2025-01
mutation AltTextUpdate($files: [FileUpdateInput!]!) {
fileUpdate(files: $files) {
files { ... on MediaImage { id alt } }
userErrors { field message code }
}
}
Session Tracking
Claude MUST emit the following output at each stage. This is mandatory.
On start, emit:
╔══════════════════════════════════════════════╗
║ SKILL: <skill name> ║
║ Store: <store domain> ║
║ Started: <YYYY-MM-DD HH:MM UTC> ║
╚══════════════════════════════════════════════╝
After each step, emit:
[N/TOTAL] <QUERY|MUTATION> <OperationName>
→ Params: <brief summary of key inputs>
→ Result: <count or outcome>
If dry_run: true, prefix every mutation step with [DRY RUN] and do not execute it.
On completion, emit:
For format: human (default):
══════════════════════════════════════════════
OUTCOME SUMMARY
<Metric label>: <value>
Errors: 0
Output: <filename or "none">
══════════════════════════════════════════════
For format: json, emit:
{
"skill": "<skill-slug>",
"store": "<domain>",
"started_at": "<ISO8601>",
"completed_at": "<ISO8601>",
"dry_run": false,
"steps": [
{
"step": 1,
"operation": "<OperationName>",
"type": "query",
"params_summary": "<string>",
"result_summary": "<string>",
"skipped": false
}
],
"outcome": {
"metric_key": 0,
"errors": 0,
"output_file": null
}
}
Output Format
human: count of images updated + a CSV (product, image_id, old_alt, new_alt). json: { images_updated, images_skipped, errors, output_file }.
Error Handling
| Error | Cause | Recovery |
|---|---|---|
THROTTLED | API rate limit | Wait 2s, retry up to 3 times |
userErrors non-empty | Invalid file id / not a MediaImage | Log message, skip, continue |
| Alt exceeds limit | Generated text too long | Trim to max_chars at a word boundary |
Best Practices
overwrite: false for the first pass to fix the worst gap (blanks) safely; do a reviewed overwrite: true pass later for filename-style alts.shopify-admin-agentic-readiness-audit afterward to confirm the alt-text coverage pillar moved.