Conciseness

The body is mostly high-value non-obvious domain knowledge, but there is more than minor padding: the Background section re-explains trimmer/reachability basics Claude already knows, and the 'do not explore the codebase' guardrail is repeated four times (procedure blockquote, Step 3, Step 4, Stop Signals). Not 4: the repetition and concept re-explanation go beyond 'minor instances that could be trimmed'. Not 2: most sections (fix recipes, gotchas, commands) earn their tokens.

Actionability

Nearly everything is copy-paste ready: exact csproj XML with MSBuild condition, build/grep commands, and before/after C# for each strategy. Not 5: the Strategy C sample decorates the context class with a nonexistent '[JsonSerializerContext]' attribute (the generator keys off the JsonSerializerContext base class), so that snippet fails to compile as written; the rest is executable.

Workflow Clarity

Steps 1–6 are clearly sequenced with explicit feedback loops: 'fix a small batch of warnings (5-10), then rebuild immediately', Step 5 rebuild-and-repeat until 0 warnings, and Step 6 validation across all TFMs (0 IL warnings, no NETSDK1210, clean older-TFM builds) plus a final checklist. Not 4: validation checkpoints are explicit and repeated at every stage, not merely present.

Progressive Disclosure

Clean section structure with a real, verified one-level reference (references/polyfills.md, correctly linked from the Polyfills section) and clearly labeled external links. Not 5: the body inlines content that could be split out — the full warning-code catalog, the Common Gotchas with long code samples — making the SKILL.md longer than an overview-plus-pointers ideal.

Specificity

The description lists multiple specific concrete actions — 'systematically resolving IL trim/AOT analyzer warnings', 'fixing trimming warnings', 'resolving IL warnings (IL2026, IL2070, IL2067, IL2072, IL3050)', 'adding DynamicallyAccessedMembers annotations', 'enabling IsAotCompatible' — covering the full workflow comprehensively. Not 4: there are no minor gaps in coverage; every action in the skill's scope is named.

Completeness

Both what and when are explicit: 'Make .NET projects compatible with Native AOT and trimming by systematically resolving IL trim/AOT analyzer warnings' (what) followed by explicit 'USE FOR:' and 'DO NOT USE FOR:' clauses with concrete triggers (when). Not 4: the when-guidance is explicit and enumerated rather than merely present.

Trigger Term Quality

Trigger terms are exactly what an affected user would say: 'make my project AOT-compatible', 'fix trimming warnings', plus the specific IL codes (IL2026, IL2070, IL2067, IL2072, IL3050) that users paste directly from build output. Not 4: coverage includes the natural synonyms ('AOT-compatible', 'trimming', 'IL warnings') and the exact technical tokens users search on.

Distinctiveness Conflict Risk

It occupies a clear niche (.NET Native AOT/trimming compatibility) with explicit boundary setting via 'DO NOT USE FOR: publishing native AOT binaries, optimizing binary size, replacing reflection-heavy libraries'. Conflict risk with adjacent skills (e.g., a publishing skill) is explicitly managed.