Platform References

Platform Documentation References

Purpose: This file documents all external platform documentation sources used during the design and implementation of the document-accessibility-wizard agent system. Other agents and contributors can use these references to understand the platform capabilities leveraged by this project, verify implementation patterns, and stay current with upstream changes.

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Table of Contents

• Claude Code (Anthropic)
• VS Code / GitHub Copilot
• Model Context Protocol (MCP)
• Accessibility Standards
  • WCAG and W3C
  • Compliance Frameworks
  • Microsoft Office Accessibility
  • Adobe PDF Accessibility
  • Deque University and axe-core
• Feature-to-Source Mapping

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Claude Code (Anthropic)

Base URL: https://code.claude.com/docs/en/

Note: URLs previously hosted at docs.anthropic.com/en/docs/claude-code/ now redirect to code.claude.com/docs/en/.

Topic	URL	What We Learned
Sub-agents	https://code.claude.com/docs/en/sub-agents	Custom subagent frontmatter fields (name, description, tools, disallowedTools, model, permissionMode, maxTurns, skills, mcpServers, hooks, memory, background, isolation). Built-in subagents: Explore, Plan, General-purpose. Scope hierarchy and memory scopes. Background vs foreground execution. Worktree isolation via isolation: "worktree".
Hooks	https://code.claude.com/docs/en/hooks	18 hook events including SessionStart, SessionEnd, PreToolUse, PostToolUse, SubagentStart, SubagentStop, TeammateIdle, TaskCompleted. Three handler types: command, prompt, agent. Async hooks. Hook locations: user settings, project settings, plugin, skill/agent frontmatter.
Hooks guide	https://code.claude.com/docs/en/hooks-guide	Practical hook examples and patterns for validation, quality gates, and automation workflows.
Memory	https://code.claude.com/docs/en/memory	Memory types: managed policy, project (CLAUDE.md), project rules (.claude/rules/*.md with paths frontmatter), user (~/.claude/CLAUDE.md), project local (CLAUDE.local.md), auto memory (MEMORY.md - first 200 lines loaded). Imports with @path syntax.
Skills	https://code.claude.com/docs/en/skills	Agent Skills standard with SKILL.md files. Frontmatter: name, description, disable-model-invocation, user-invocable, allowed-tools, model, context, agent, hooks, argument-hint. Supporting files pattern. Skill scopes: enterprise > personal > project. Plugin skills use namespace. Dynamic context injection with !command`` syntax.
Agent teams	https://code.claude.com/docs/en/agent-teams	Experimental multi-agent orchestration. Teams vs subagents comparison. Team lead + teammates + task list + mailbox architecture. Display modes (in-process, split panes via tmux/iTerm2). Quality gates via TeammateIdle and TaskCompleted hooks. Requires CLAUDE_CODE_EXPERIMENTAL_AGENT_TEAMS=1.
Plugins	https://code.claude.com/docs/en/plugins	Plugin structure (.claude-plugin/plugin.json manifest). Plugin components: skills, agents, hooks, MCP servers, LSP servers, settings. Namespaced skills (/plugin:skill). Plugin vs standalone comparison. Migration from .claude/ standalone config.
Plugins reference	https://code.claude.com/docs/en/plugins-reference	Full plugin manifest schema. Plugin directory structure specification. Debugging and development tools. Version management with semver.
Model configuration	https://code.claude.com/docs/en/model-config	Model aliases (default, sonnet, opus, haiku, opusplan). Setting model via CLI, env var, settings. CLAUDE_CODE_SUBAGENT_MODEL for subagent model control. 1M token extended context. Effort levels (low/medium/high). Enterprise model restrictions via availableModels.
Settings	https://code.claude.com/docs/en/settings	Settings hierarchy (CLI flag > project > user > plugin). Environment variables. Settings files for permissions, hooks, model config.
MCP in Claude Code	https://code.claude.com/docs/en/mcp	MCP server integration in Claude Code. Tool matching via mcp__<server>__<tool> pattern for hooks.
Checkpointing	https://code.claude.com/docs/en/checkpointing	File state snapshots for safe rollback during agent operations.
Headless/SDK	https://code.claude.com/docs/en/headless	Headless mode for CI/CD integration and programmatic Claude Code usage.
CLI reference	https://code.claude.com/docs/en/cli-reference	Complete CLI flags and options reference.

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VS Code / GitHub Copilot

VS Code Custom Agents

Topic	URL	What We Learned
Custom agents	https://code.visualstudio.com/docs/copilot/customization/custom-agents	.agent.md file format. YAML frontmatter: description, name, tools, agents, model, user-invokable, disable-model-invocation, target, mcp-servers, handoffs. Handoff configuration (label, agent, prompt, send, model). VS Code also detects .md files in .claude/agents/ for cross-platform compatibility. Claude agent format support with comma-separated tools. Organization-level agent sharing.
Agent overview	https://code.visualstudio.com/docs/copilot/agents/overview	Built-in agents (Agent, Plan, Ask). Agent types: Local, Background, Cloud, Third-party. Session handoff between agent types.
Chat overview	https://code.visualstudio.com/docs/copilot/chat/copilot-chat	Chat surfaces (Chat view, Inline chat, Quick chat, CLI). Agent picker, model picker. Context mechanisms (#-mentions, @-mentions, vision). Review and checkpoint system.
AI extensibility	https://code.visualstudio.com/api/extension-guides/ai/ai-extensibility-overview	Extension options: Language Model Tools, MCP Tools, Chat Participants, Language Model API. Decision matrix for choosing approach.
Custom instructions	https://code.visualstudio.com/docs/copilot/customization/custom-instructions	Instruction file types and loading behavior.
Agent skills	https://code.visualstudio.com/docs/copilot/customization/agent-skills	Skill directories with SKILL.md entrypoint. Workspace paths: .github/skills/, .claude/skills/, .agents/skills/. Personal paths: ~/.copilot/skills/, ~/.claude/skills/, ~/.agents/skills/.
Hooks	https://code.visualstudio.com/docs/copilot/customization/hooks	Published 2026-02-09 (Preview, VS Code 1.109.3+). Eight lifecycle events: SessionStart, UserPromptSubmit, PreToolUse, PostToolUse, PreCompact, SubagentStart, SubagentStop, Stop. Hook files: workspace -> .github/hooks/*.json; user -> ~/.claude/settings.json. JSON format: { "hooks": { "EventName": [{ "type": "command", "command": "...", "windows": "...", "timeout": 30 }] } }. Exit code 0 = success, 2 = blocking error. additionalContext field injects text into agent conversation.
MCP servers in VS Code	https://code.visualstudio.com/docs/copilot/customization/mcp-servers	MCP server configuration in VS Code settings.
Prompt files	https://code.visualstudio.com/docs/copilot/customization/prompt-files	.prompt.md files for reusable workflows.

GitHub Copilot Documentation

Topic	URL	What We Learned
Custom instructions	https://docs.github.com/en/copilot/how-tos/configure-custom-instructions/add-repository-instructions	Three types: repository-wide (copilot-instructions.md), path-specific (*.instructions.md with applyTo frontmatter), agent instructions (AGENTS.md, CLAUDE.md, GEMINI.md). excludeAgent frontmatter for targeting specific agents. Priority: personal > repository > organization.
MCP in Copilot	https://docs.github.com/en/copilot/concepts/context/mcp	MCP protocol overview for Copilot. GitHub MCP server. GitHub MCP Registry. Remote and local MCP server support. Toolset customization.
Copilot extensions	https://docs.github.com/en/copilot/building-copilot-extensions	Building Copilot extensions with agents and skills.
Agent mode	https://docs.github.com/en/copilot/using-github-copilot/coding-agent	Copilot coding agent for autonomous task execution.

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Model Context Protocol (MCP)

Topic	URL	What We Learned
MCP specification	https://modelcontextprotocol.io/	Open protocol for LLM-to-tool communication. Tools, resources, prompts, and sampling primitives. JSON-RPC 2.0 transport.
MCP TypeScript SDK	https://github.com/modelcontextprotocol/typescript-sdk	@modelcontextprotocol/sdk package. Server and client implementation. StdioServerTransport for stdio-based MCP servers.
MCP servers repo	https://github.com/modelcontextprotocol/servers	Reference MCP server implementations. Community server examples.
MCP inspector	https://modelcontextprotocol.io/docs/tools/inspector	Testing and debugging MCP servers during development.

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Accessibility Standards

WCAG and W3C

Topic	URL	What We Learned
WCAG 2.2 Specification	https://www.w3.org/TR/WCAG22/	Web Content Accessibility Guidelines version 2.2. Defines 31 Level A and 24 Level AA success criteria. 4.1.1 Parsing removed (always satisfied in modern user agents). New criteria: 2.4.11 Focus Not Obscured, 2.4.13 Focus Appearance (AAA), 2.5.7 Dragging, 2.5.8 Target Size, 3.2.6 Consistent Help, 3.3.7 Redundant Entry, 3.3.8 Accessible Authentication, 3.3.9 Accessible Authentication Enhanced (AAA).
WCAG 2.2 Understanding Docs	https://www.w3.org/WAI/WCAG22/Understanding/	Informative companion to WCAG 2.2. Explains each success criterion with intent, benefits, examples, techniques, and test procedures. URL pattern: {base}{slug} where slug is the kebab-case criterion name (e.g., non-text-content for 1.1.1). Used by CSV reporters to generate wcag_url column values.
WCAG 2.2 Quick Reference	https://www.w3.org/WAI/WCAG22/quickref/	Customizable quick reference to all WCAG success criteria and techniques. Allows filtering by level (A, AA, AAA), technology, and topic. Used for cross-checking criterion levels and applicability.
WCAG 2.2 Techniques	https://www.w3.org/WAI/WCAG22/Techniques/	Sufficient, advisory, and failure techniques for meeting each WCAG criterion. Techniques are informative (not normative). Used to inform fix steps and remediation guidance in agent rules.

Compliance Frameworks

Topic	URL	What We Learned
PDF/UA (ISO 14289-1)	https://pdfa.org/resource/iso-14289-pdfua/	Universal Accessibility standard for PDF documents. Tagged PDF requirements.
Matterhorn Protocol 1.1	https://pdfa.org/resource/the-matterhorn-protocol/	PDF/UA conformance testing rules. 136 failure conditions organized into 31 checkpoints.
VPAT 2.5 / ACR	https://www.itic.org/policy/accessibility/vpat	Voluntary Product Accessibility Template. Accessibility Conformance Report format for compliance documentation.
Section 508	https://www.section508.gov/	US federal accessibility requirements. Trusted tester methodology.
EN 301 549	https://www.etsi.org/deliver/etsi_en/301500_301599/301549/	European accessibility standard for ICT products and services.

Microsoft Office Accessibility

These pages define the official Accessibility Checker rules and per-format remediation guidance. They are the authoritative source for our DOCX-*, XLSX-*, and PPTX-* rule IDs, severity classifications (Error/Warning/Tip), and fix step text.

Topic	URL	What We Learned
Accessibility Checker Rules	https://support.microsoft.com/en-us/office/rules-for-the-accessibility-checker-651e08f2-0fc3-4e10-aaca-74b4a67101c1	Complete list of every rule the built-in Accessibility Checker enforces across Word, Excel, PowerPoint, Outlook, OneNote, and Visio. Classifies each rule as Error, Warning, Tip, or Intelligent Services. Covers: alt text on all objects, table column headers, section/slide/sheet naming, document access restrictions, content control field titles, simple table structure, contrast, captions, reading order, heading styles, and unique slide titles. Also documents checker limitations (color-only info, in-band captions). This is the single most important reference for our document rule definitions.
Accessibility Guide for Microsoft 365 Apps	https://learn.microsoft.com/en-us/microsoft-365-apps/deploy/accessibility-guide	Admin-oriented guidance for deploying accessible Microsoft 365 environments. Documents connected experiences for accessibility (live captions, dictation, read aloud, learning tools, automatic alt text, QuickStarter). Covers Group Policy to enable "Check for accessibility issues while editing" for Word, Excel, and PowerPoint. Lists accessibility resources organized by disability category.
Improve Accessibility with the Accessibility Checker	https://support.microsoft.com/en-us/office/improve-accessibility-with-the-accessibility-checker-a16f6de0-2f39-4a2b-8bd8-5ad801426c7f	How-to for running the Accessibility Checker in each Office app. Describes results pane (Errors, Warnings, Tips, Intelligent Services categories). Used as the general fallback help URL for unmapped Office issues.
Word: Make Documents Accessible	https://support.microsoft.com/en-us/office/make-your-word-documents-accessible-d9bf3683-87ac-47ea-b91a-78dcacb3c66d	Format-specific guidance for Word. Bookmark anchors for each topic: #bkmk_doctitle, #bkmk_headings (now #bkmk_useheadings), #bkmk_tableheaders, #bkmk_hyperlinks, #bkmk_contrast (now #bkmk_color), #bkmk_language, #bkmk_layout (now #bkmk_tableslayouts), #bkmk_toc, #bkmk_whitespace, #bkmk_watermarks. These anchors are used in help-url-reference SKILL to build per-rule help URLs.
Excel: Make Workbooks Accessible	https://support.microsoft.com/en-us/office/make-your-excel-documents-accessible-6cc05fc5-1314-48b5-8eb3-683e49b3e593	Format-specific guidance for Excel. Bookmark anchors: #bkmk_sheettabs, #bkmk_tableheaders, #bkmk_mergedcells (now #bkmk_simpletablestructure), #bkmk_color (now #bkmk_usecolor), #bkmk_alttext, #bkmk_fontformat, #bkmk_hyperlinks, #bkmk_validation, #bkmk_doctitle.
PowerPoint: Make Presentations Accessible	https://support.microsoft.com/en-us/office/make-your-powerpoint-presentations-accessible-6f7772b2-2f33-4bd2-8ca7-dae3b2b3ef25	Format-specific guidance for PowerPoint. Bookmark anchors: #bkmk_slidetitles, #bkmk_readingorder, #bkmk_alttext, #bkmk_tableheaders, #bkmk_captions, #bkmk_contrast (now #bkmk_color), #bkmk_animations, #bkmk_transitions, #bkmk_hyperlinks (now #bkmk_links).
Alt Text: Add to Objects	https://support.microsoft.com/en-us/office/add-alternative-text-to-a-shape-picture-chart-smartart-graphic-or-other-object-44989b2a-903c-4d9a-b742-6a75b451c669	Cross-app alt text instructions (Word, Excel, PowerPoint, Outlook). Covers shapes, pictures, charts, SmartArt, and other objects. Used as the help URL for alt text Error rules (DOCX-E001, XLSX-E001, PPTX-E002) and decorative image Warning rules.
Alt Text: Write Effective Alt Text	https://support.microsoft.com/en-us/office/everything-you-need-to-know-to-write-effective-alt-text-df98f884-ca3d-456c-807b-1a1fa82f5dc2	Guidance on writing meaningful alt text. Covers when to use alt text vs marking as decorative, length guidelines, and do/don't examples. Used as help URL for long alt text Warning rules.
Word: Accessible Tables	https://support.microsoft.com/en-us/office/create-accessible-tables-in-word-cb464015-59dc-46a0-ac01-6217c62210e5	Detailed table accessibility in Word. Header row designation, simple structure requirements, avoiding nested/merged/split cells. Used as help URL for DOCX-E003 (table headers).

Adobe PDF Accessibility

Topic	URL	What We Learned
Creating Accessible PDFs	https://helpx.adobe.com/acrobat/using/creating-accessible-pdfs.html	Acrobat Pro guide to PDF accessibility. Anchor-based sections map to our PDFUA.* and PDFBP.* rule IDs: #tag_pdf (TaggedPDF), #add_title (Title), #set_language (Language), #bookmarks (BookmarksPresent), #alt_text (AltText), #tables (TableHeaders), #reading_order (ReadingOrder), #headings (Headings), #lists (ListTags), #contrast (Contrast), #scanned (Scanned), #ocr (Searchable).
PDF Accessibility Checker (PAC)	https://pdfua.foundation/en/pdf-accessibility-checker-pac	Free tool for checking PDF/UA conformance. Implements Matterhorn Protocol checks. Used as reference for PDFUA rule definitions.

Deque University and axe-core (Web Accessibility)

Topic	URL	What We Learned
axe-core Rules Reference	https://dequeuniversity.com/rules/axe/4.10/	Complete reference for axe-core automated accessibility rules. URL pattern: {base}{rule-id}. Each rule maps to one or more WCAG success criteria. Used as the help_url source for all web CSV findings. Covers 90+ rules including image-alt, color-contrast, label, button-name, link-name, html-has-lang, document-title, heading-order, aria-roles, aria-required-attr, bypass, region, tabindex, meta-viewport, autocomplete-valid, and more.
axe-core GitHub Repository	https://github.com/dequelabs/axe-core	Open-source accessibility testing engine. Rule definitions, checks, and metadata. Version 4.10 is the current reference version in our URL patterns.
Deque University Topic Pages	https://dequeuniversity.com/	Training resources for accessibility topics not covered by axe-core rules. Used for agent-detected issues: focus management (/class/focus-management2/focus/overview), live regions (/library/aria/liveregion-playground), modal dialogs (/library/aria/modal-dialog/sf-modal-dialog), data tables (/class/tables2/simple/overview).
axe-core CLI	https://www.npmjs.com/package/@axe-core/cli	CLI tool for running axe-core scans from the terminal. Used by the A11y: Run axe-core Scan VS Code task and the web-accessibility-wizard Phase 1 runtime scan.

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Feature-to-Source Mapping

This table maps each project feature to the documentation sources that informed its implementation.

Project Feature	Primary Source(s)	Notes
Custom agents (.agent.md)	VS Code Custom agents, Claude Code Sub-agents	Cross-platform format: VS Code detects .md files in .claude/agents/
Agent frontmatter (tools, model, handoffs)	VS Code Custom agents	Frontmatter fields, tool arrays, handoff configuration
Hidden helper sub-agents (user-invokable: false)	VS Code Custom agents, Claude Code Sub-agents	user-invokable: false hides from picker; disable-model-invocation prevents auto-invocation
Agent Skills (SKILL.md)	Claude Code Skills	Skill directories with SKILL.md entrypoint. Frontmatter for invocation control. Supporting files pattern.
Lifecycle hooks (SessionStart, SessionEnd)	Claude Code Hooks, VS Code Hooks	Hook events, handler types (command, prompt, agent). Quality gates via exit codes. VS Code: .github/hooks/*.json files, 8 events (SessionStart, UserPromptSubmit, PreToolUse, PostToolUse, PreCompact, SubagentStart, SubagentStop, Stop). Note: VS Code uses Stop - there is no SessionEnd event in VS Code.
Agent Teams (AGENTS.md)	Claude Code Agent teams, GitHub Custom instructions	Enterprise coordination patterns. GitHub supports AGENTS.md for agent instructions.
Persistent memory	Claude Code Memory	CLAUDE.md project memory. Auto memory with MEMORY.md. Memory scopes.
MCP server (document scanner tools)	MCP specification, MCP TypeScript SDK	11 tools + 6 prompts. @modelcontextprotocol/sdk with StdioServerTransport.
Batch scanning & severity scoring	WCAG 2.2, PDF/UA, Matterhorn Protocol	0-100 severity score with A-F grades. Cross-document pattern detection.
VPAT/ACR compliance export	VPAT 2.5 / ACR template	Accessibility Conformance Report generation from audit findings.
Cross-platform handoff	Claude Code Sub-agents, VS Code Custom agents	Shared artifacts, report format compatibility between platforms.
Plugin packaging	Claude Code Plugins, Claude Code Plugins reference	.claude-plugin/plugin.json manifest. Distribution formats: git clone, per-project Copilot, per-project Claude, plugin marketplace.
Background scanning patterns	Claude Code Sub-agents (background, isolation)	Background subagent execution. Worktree isolation for safe parallel scanning.
Delta scanning (changed files only)	Git diff integration	git diff --name-only for detecting changed documents since last commit.
Path-specific instructions	GitHub Custom instructions	applyTo glob patterns in .instructions.md frontmatter.
Custom prompts (.prompt.md)	VS Code Prompt files	9 prompt files for one-click audit workflows.
Document rule IDs (DOCX-*, XLSX-*, PPTX-*)	Accessibility Checker Rules, Word/Excel/PowerPoint accessibility pages	Rule severity (Error/Warning/Tip) derived from Checker classification. Rule descriptions and WCAG mappings maintained in accessibility-rules skill.
Document help URLs	Word/Excel/PowerPoint accessibility pages, Alt Text guidance	Bookmark-anchored URLs for per-rule fix guidance. Mapped in help-url-reference skill.
PDF rule IDs (PDFUA.*, PDFBP.*, PDFQ.*)	PDF/UA, Matterhorn Protocol, Creating Accessible PDFs	Rule definitions from ISO 14289-1 and Matterhorn failure conditions. Help URLs from Adobe Acrobat guide.
Web axe-core rule mapping	axe-core Rules Reference, axe-core GitHub	Rule IDs to Deque University help URLs. WCAG criterion mapping from axe-core metadata.
WCAG criterion-to-slug mapping	WCAG 2.2 Understanding Docs	URL pattern for linking findings to W3C Understanding documents. Used in CSV wcag_url column.
Fix step templates	Word/Excel/PowerPoint/PDF accessibility pages	Application-specific step-by-step remediation instructions derived from official Microsoft and Adobe documentation.

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Keeping References Current

These documentation sources are actively maintained by their respective platforms. When working on this project:

1. Check for breaking changes - Platform features like agent teams (experimental) and hooks may change between releases.
2. Verify URLs - Claude Code docs migrated from docs.anthropic.com to code.claude.com in 2025. Similar migrations may occur.
3. Test cross-platform compatibility - VS Code now supports Claude agent format (.md in .claude/agents/), but feature parity varies.
4. Review changelogs - Claude Code and VS Code release notes document new agent/skill/hook capabilities.

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Last updated: 2026-02-24. Expanded Accessibility Standards with Microsoft Office Checker rules, WCAG 2.2 Understanding docs, Adobe PDF sources, and Deque/axe-core references.