Part of #

Proposed Changes

• Fix broken skill path in AGENTS.md (resolved to nonexistent double-nested directory)
• Extract CSS selectors, troubleshooting, and output template from UI testing SKILL.md into references/ for progressive disclosure
• Expand AGENTS.md coverage to document abilities API, extensions, tracking, client-context, and type guards — previously undocumented areas
  covering ~60% of the codebase
• Add unit tests for src/types/guards.ts (0% → 100% coverage, +112 tests)
• Fix markdown table pipe alignment lint errors
• Remove self-rating section (never triggered by agents across 11 commits)
• Add file navigation guide to AGENTS.md so agents load the right file first

Why are these changes being made?

AGENTS.md only covered ~40% of the codebase surface area. An agent working on tracking, abilities, extensions, or type guards had no guardrails and those are among the lowest-coverage, highest-risk files. The broken skill path meant the UI testing skill was undiscoverable. The type guards file (306 lines of runtime validation at API boundaries) had zero tests, and broken guards fail silently by rejecting valid data.

Testing Instructions

Run lint, typecheck, and tests

  cd packages/image-studio
  yarn build && yarn test && yarn lint && yarn typecheck

• Install this PR to your sandbox

install-plugin.sh am forno-218/improve-agents-experience

• Enable filter

echo "<?php add_filter( 'jetpack_image_studio_enabled', '__return_true' );" > ~/public_html/wp-content/mu-plugins/enable-image-studio.php

• Test Image Studio in Media Library and Block Editor
• Or just ask AI to run Image Studio comprehensive browser tests

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you tested accessibility for your changes? Ensure the feature remains usable with various user agents (e.g., browsers), interfaces (e.g., keyboard navigation), and assistive technologies (e.g., screen readers) (PCYsg-S3g-p2).
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?