The body is lean with no concept explanations — sections cover only the call signature, parameter table, return value, and an example, so every token earns its place per the level-3 anchor.

It provides a fully executable Python call with concrete arguments plus a parameter table with types and defaults and a copy-paste usage example, matching the level-3 anchor for executable, copy-paste-ready guidance.

This is a single-purpose skill with one unambiguous action (download and save an image); per the simple-skills scoring note a clear single action can score 3, and there is no batch/destructive operation requiring validation.

The body is under 50 lines with no external references needed and is organized into clear sections, satisfying the simple-skills note that such skills can score 3 on progressive disclosure with just well-organized sections.

It names the domain and two concrete actions — "下载图片" and "保存到本地" — but does not list a comprehensive set of multiple specific actions, matching the level-2 anchor rather than level 3.

It explicitly answers both what ("下载图片并保存到本地") and when ("当用户提到...时使用"), matching the level-3 anchor for explicit triggers rather than the implied-only level 2.

"下载图片、抓图、图片下载、网络图片保存" provides good coverage of natural terms a user would say, matching the level-3 anchor and exceeding the 'some relevant keywords' bar of level 2.

The image-download niche with distinct triggers (抓图, 网络图片保存) is unlikely to conflict with other skills, matching the level-3 anchor; it is not merely 'somewhat specific' as at level 2.