Conciseness

There is no fluff and no re-teaching of known concepts (CSS keyframes, GSAP, background-clip are assumed), but key rules are systematically restated: root-container "opacity:1" appears in 使用方式, 实片排版, and 渲染契约; render-from-0s and the no-"infinite" rule appear twice (lines 23 and 76); screenCopy completeness/once-only appears twice (lines 21 and 75). This is more than minor trimmable over-explanation, so it fits 'mostly efficient but could be tightened' rather than 4.

Actionability

Guidance is highly concrete: named fonts (PingFang SC / Noto Sans CJK SC / Microsoft YaHei), numeric ranges (中文 3.5%–6.5%、英文 1.6%–2.4% of canvas width; 0.3–0.8s entrance; ≥约3s label reading), exact CSS mechanics (background-clip:text, animation-fill-mode:both/forwards, data-motion-exit values), a copy-paste-ready JSON output contract, and the window.__hf={duration,seek(t,o)} API. Not 5: no worked HTML/CSS example of an actual caption design, which is the skill's primary artifact.

Workflow Clarity

The flow is unambiguous ("直接设计当前字幕，并按文末契约返回 JSON，不输出计划或调用其他工具") and includes two explicit checkpoints: "核对一次 HTML 的全部可见文字…应与本次 screenCopy 完全相同" and "提交前检查入场、流光高光经过、稳定期与末态". Not 5: the sequence is embedded in prose rather than ordered steps, and there is no error-recovery loop for a failed check.

Progressive Disclosure

Five well-organized sections plus a semantic effects table, and every path mentioned exists at runtime (no skill bundle files are referenced; vendor/gsap.min.js is a runtime library). Not 5: at roughly 60 dense lines — above the simple-skill threshold — the detailed rendering contract and material/motion specifications could be split into a one-level-deep reference file.

Specificity

"为'非正式发布会'官方模板设计或修改全屏视频内的中英双语花字，包括渐变材质字、流光、关键词动效、造型标签与实片排版" enumerates five concrete deliverable types (gradient-material type, light sweeps, keyword motion, look labels, footage layout) on top of the design/modify actions — comprehensive within the declared scope. Not 4: no visible coverage gaps inside that niche.

Completeness

Both halves are explicit: the "what" (design/modify bilingual on-video caption typography with the enumerated effects) and the "when" ("仅在选用该模板或用户明确要求该模板的字幕风格时使用"), reinforced by explicit exclusions (won't restyle normal captions, won't generate video or music). Not 4: the trigger condition is fully concrete, not merely present-but-vague.

Trigger Term Quality

Natural keywords are present — "花字", "字幕风格", "官方模板", "非正式发布会" — and would match how a user requests this skill. Not 5: despite the bilingual use case, no English trigger phrasings or further synonyms of the template name are included, so a few natural terms are missing.

Distinctiveness Conflict Risk

The skill is pinned to a single named official template and explicitly disclaims adjacent territory ("不改变普通字幕的默认样式，不负责生成底层视频或配乐"), giving it a clear niche with minimal risk of firing for generic caption or video skills. Not 4: the explicit non-goals remove even minor overlap with closely related skills.