Conciseness

The body is lean and non-padded: every section carries agent-specific knowledge (paths, sandbox behavior, settings restart), and the manifest starters are tight. Two minor over-explanations keep it below the 5 anchor: the second manifest example largely duplicates the first (adding only `content_scripts`/`host_permissions`), and lines like "Prefer content scripts for page-local behavior and service workers for coordination" restate MV3 architecture Claude already knows.

Actionability

Most guidance is executable: concrete paths (`/a0/usr/browser-extensions/<slug>/`), a complete copy-paste manifest V3 starter, specific URL shapes for store links, and an explicit enable step. The gap is step 4 of the install flow — "download the CRX from Chrome's update service, extract the ZIP payload safely" gives no actual URL format or command, so the trickiest step is high-level only; this fits the 4 anchor ("concrete code or commands with minor gaps") rather than the 5 anchor's fully copy-paste-ready coverage.

Workflow Clarity

Both workflows are clearly sequenced with checkpoints: create validates JSON syntax and `manifest_version: 3` (step 5), install gates on user risk acceptance (steps 1 and 6), and a final Review Checklist covers the risky-operation validation. It falls short of the 5 anchor because there are no error-recovery/feedback loops (e.g. what to do when the manifest fails validation or the CRX download fails) and the manual CRX install path lacks a verification step for the extracted payload beyond "inspect manifest.json".

Progressive Disclosure

The skill is a single self-contained file with no references/, scripts/, or assets/ bundle (verified on disk), and everything fits comfortably inline at ~100 lines. Section headers (Operating Model, Safety First, Create New Extension, Install From Chrome Web Store, Review Checklist) make navigation trivial with nothing buried, matching the rubric's exception that a compact skill with well-organized sections and no need for external references scores 5.

Specificity

The description lists four concrete actions — "Build, edit, install or audit" — against a precisely named domain ("Chrome Web Store extensions in Agent Zero Browser"), covering the full lifecycle the skill supports. This matches the 5 anchor (multiple specific concrete actions, comprehensive coverage) and exceeds the 4 anchor's "minor gaps in coverage" since the four verbs map to the skill's four workflows.

Completeness

The "what" is clearly answered (build/edit/install/audit extensions for Agent Zero Browser) but the description contains no "Use when..." clause or equivalent explicit trigger phrasing; per the judging guideline this caps completeness at 3. The separate frontmatter `triggers` list partially mitigates, but the description field itself has the "when" only weakly implied, keeping it at the 3 anchor rather than the 4 anchor's explicit-but-imperfect "when".

Trigger Term Quality

Strong natural keywords are present: "build", "install", "edit", "audit", "Chrome Web Store extensions", "browser" — phrases users would naturally say when requesting an extension. A few natural terms are missing from the description itself (e.g. "browser extension" as a plain phrase, "manifest", "extension permissions"), matching the 4 anchor "good keyword coverage; a few natural terms missing" rather than the 5 anchor's synonym/extension completeness.

Distinctiveness Conflict Risk

"Chrome Web Store extensions in Agent Zero Browser" carves out a clear niche tied to a specific product and plugin scope, with distinct verbs unlikely to fire for unrelated skills. Conflict risk is minimal — this fits the 5 anchor ("clear niche with distinct triggers") and is well above the 4 anchor's "minor overlap risk with closely related skills".