Conciseness

The body is dominated by tight before/after code pairs and mapping rules that earn their tokens, but a few brief passages re-explain Web Forms mechanics Claude already knows (e.g., 'ASP.NET Web Forms User Controls (.ascx files) are reusable markup fragments with code-behind' and the Web.config tag-prefix walkthrough). This fits 'efficient; minor instances of over-explanation that could be trimmed' rather than the level-5 anchor, where every token earns its place, and is clearly above level 3's 'some unnecessary explanation'.

Actionability

Every rule and pattern ships executable, copy-paste-ready code (the [Parameter] and EventCallback conversions, the @inherits/partial-class pairing, the DynamicComponent equivalent for LoadControl, the FindControl and Page_Load examples), plus a concrete error signature ('you'll get CS0263. Add it manually'). Specific examples cover the common cases, matching the level-5 anchor.

Workflow Clarity

The CLI's processing steps are tabulated, error-recovery guidance exists for the base-class mismatch, and the closing checklist provides verification points ('Code-behind compiles with updated usings', 'Component renders expected HTML output'). However, the agent's own procedure is never laid out as a sequenced workflow — the ordering is implicit in the rules/patterns layout — so it fits level 4 ('clear sequence with most checkpoints present; minor validation gaps') rather than level 5's explicit ordered steps with feedback loops.

Progressive Disclosure

The body is well-sectioned (CLI behavior table, critical rules, L2 patterns, file structure, checklist) and ends with a clearly signaled Reference section, matching 'good structure; most content is appropriately placed; references mostly clear'. It falls short of level 5 because the references point outside the skill bundle to '../../docs/Migration/...' and '../../src/...' paths that do not exist alongside the skill, so navigation to deeper material is not verifiable and some pattern detail is inlined that could live in reference files.

Specificity

The description lists five concrete capabilities ('ASCX-to-Razor conversion, code-behind preservation, tag prefix resolution, property/event mapping, and partial-class base class alignment'), giving comprehensive coverage of the skill's actions rather than vague domain language. It matches the anchor 'lists multiple specific concrete actions; comprehensive coverage' and exceeds the level-4 anchor, which allows minor gaps in coverage.

Completeness

Both questions are answered explicitly: the 'what' is the migration action with its five covered areas, and the 'when' is an explicit WHEN clause with concrete trigger phrases. This matches the level-5 anchor exactly and is stronger than level 4, where the 'when' would be present but less explicit.

Trigger Term Quality

Trigger phrases are natural user utterances ('migrate ascx', 'convert user control', 'ascx to blazor', 'user control migration') and the description also names the '.ascx' file extension, matching the anchor 'comprehensive coverage of natural terms including synonyms and file extensions'. No generic jargon-only phrasing that would pull it to level 3 or 4.

Distinctiveness Conflict Risk

The niche is narrow (ASCX user controls specifically) and the description actively disambiguates by routing full-page migration to '/bwfc-migration' and WebControl-based controls to '/bwfc-custom-control-migration', reducing conflict risk with sibling skills. This is a clear niche with distinct triggers, the level-5 anchor.