Conciseness

The body is dense, SDK-specific reference material with no concept padding — every statement (e.g., "a writer left open keeps the reader waiting until its process exits") describes engine behavior Claude cannot know. Version-sensitive notes are consolidated in the 'Observers and local dispatch (0.25)' section and attached to the deprecated APIs rather than expressed as time-conditional instructions, so there is nothing to trim for anchor 4.

Actionability

Install commands are copy-paste ready per language ("cargo add iii-sdk", "go get github.com/iii-hq/iii/sdk/packages/go/iii"), each language has an executable minimal example, and the Common API Map gives exact signatures like "register_worker(address, options?)". Coverage of the common cases in all five languages matches anchor 5.

Workflow Clarity

Content is organized in use order (Install → Choose the SDK → API map → per-language usage → cross-cutting concerns) with clear boundary routing to sibling skills, and no destructive or batch operations require validation checkpoints. It sits above anchor 3 (checkpoints missing for a process that needs them) but below anchor 5, since no explicit stepwise path with checkpoints is laid out for a newcomer.

Progressive Disclosure

The full five-language API reference (~250 lines) is inlined in SKILL.md with no references/ bundle files; the per-language sections and channels/namespaces detail fit anchor 3's 'content that should be separate is inline'. It is not anchor 2 (structure is strong with clear headers and easy navigation) nor anchor 4 (the bulk reference material is not split into separate files, though deferral to sibling skills like `iii-observe` is clearly signaled in Boundaries).

Specificity

The description enumerates concrete capabilities — "package installation, worker initialization, function/trigger registration, observers, invocation, local dispatch, channels, logging, OpenTelemetry" — across five named language targets, giving comprehensive coverage. It clearly matches the anchor-5 'multiple specific concrete actions; comprehensive coverage' rather than anchor 4, which requires minor gaps in coverage.

Completeness

It explicitly answers both when ("Use when working with iii SDK APIs across Node.js, browser, Python, Rust, or Go") and what (the enumerated capability list), with concrete trigger conditions. This matches anchor 5 exactly; anchor 4 would require the 'when' to be less explicit or specific, which it is not.

Trigger Term Quality

Natural domain terms users would say are well covered ("iii SDK", "Node.js", "Python", "Rust", "Go", "channels", "OpenTelemetry"), but common synonyms like "TypeScript"/"JavaScript" are omitted even though the body targets TypeScript. This fits anchor 4 ('good keyword coverage; a few natural terms missing') better than anchor 5's requirement of synonyms and variations.

Distinctiveness Conflict Risk

The iii SDK language-API niche is clear and mostly distinct, but listing "observers" and "trigger registration" overlaps with the sibling `iii-observe` skill that the body itself defers to for the observe model. This is minor overlap with a closely related skill (anchor 4), not the minimal conflict risk of anchor 5 and well above anchor 3.