Conciseness

The body is lean: terse section headers, executable snippets, a two-row decision table, and one-line comments like "Data last enables partial application". Two minor trims keep it at anchor 4 rather than 5: the pipe/flow semantics line ("= fn3(fn2(fn1(startValue)))") restates a concept Claude already knows, and the pipe and flow examples run the identical trim/uppercase/split transformation, duplicating the demo.

Actionability

The pipe and flow examples are complete and copy-paste runnable with outputs shown ("['HELLO', 'WORLD']"), and the When-to-Use table gives a concrete decision rule. The later snippets reference undefined bindings ("user", "users", "User", "users1", "users2"), so they are illustrative rather than fully executable — anchor 4 (mostly executable, minor gaps) instead of anchor 5.

Workflow Clarity

This is a simple single-task lookup skill with no multi-step process and no destructive or batch operations, so the simple-skill exception applies: the single action (pick pipe vs flow and apply the pattern) is unambiguous, and the "When to Use" table plus parallel examples make the decision immediate. It is not below 5 because there are no fragile steps requiring validation checkpoints.

Progressive Disclosure

The skill is short with no external references needed; no references/, scripts/, or assets/ bundle exists to link. Content is well-organized into clearly headed sections (pipe, flow, when to use, fp-ts types, common pattern), which matches the simple-skill case for a top progressive-disclosure score. Nothing that belongs in a separate file is inlined.

Specificity

The description names the domain ("Quick reference for pipe and flow" in fp-ts) and carries a couple of concrete capabilities via the when-clause ("chain functions, compose operations, or build data pipelines"), but the 'what' is led by the generic label 'Quick reference' rather than specific actions. It matches anchor 3 (domain plus 1-2 concrete actions, not comprehensive); it is above anchor 2 because pipe/flow and chaining/composing are concrete, but below anchor 4 because it never says what the skill actually shows (e.g., transforming values, building reusable compositions, combining with Option/Array).

Completeness

Both halves exist: 'what' ("Quick reference for pipe and flow") and an explicit 'when' ("Use when user needs to chain functions, compose operations, or build data pipelines in fp-ts"). It falls just short of anchor 5 because the 'what' is thin — it does not state what the reference covers (transforming values, creating reusable pipelines, fp-ts type combinators) — while the 'when' is explicit and specific, placing it above anchor 3.

Trigger Term Quality

Natural phrases are present: "chain functions", "compose operations", "build data pipelines", plus the technical anchors "pipe", "flow", "fp-ts". Good coverage but missing common variations users would say, such as "function composition", "pipe functions together", or "compose/pipeline utilities", so it fits anchor 4 rather than the comprehensive synonym coverage of anchor 5.

Distinctiveness Conflict Risk

The fp-ts scope gives it a clear niche with minimal conflict risk, but the trigger phrases "chain functions" and "compose operations" are generic functional-programming vocabulary that also applies to lodash, Ramda, and RxJS, so a closely related skill could overlap. This is anchor 4 (mostly distinct, minor overlap risk with closely related skills) rather than anchor 5.