Conciseness

The body is dense, table-driven, and nearly free of padding, but has minor trimmable instances: the 'Requires Go 1.24+' version pin and slight editorial framing ('Equally important, the fastlike source code is the most complete programmatic specification...'). Nothing explains concepts Claude already knows, so it sits above 3 but short of 'every token earns its place'.

Actionability

Fully executable throughout: git clone/make build, go install, runnable invocations for the minimal, named-backend, hot-reload, profiler, and full-config cases, plus complete flag tables with defaults and security notes for -profile-ui. Copy-paste-ready commands cover the common cases.

Workflow Clarity

A coherent Install -> Quick Start -> Configurations -> Profiler progression exists with a preemptive failure-mode note (macOS port 5000) and an observable outcome ('Open http://localhost:6060/ for the trace index'), but there are no explicit build/install verification steps or error-recovery guidance. No destructive or batch operations, so the cap-3 rule does not apply.

Progressive Disclosure

Clear overview body with well-signaled, one-level-deep references: all 7 referenced files (abi.md, backends.md, build.md, config.md, profiling.md, test.md, understanding-compute-from-source.md) exist in references/, reference files point to the external fastlike repo rather than nesting further, and the References table provides topic + 'use when' navigation.

Specificity

'Runs Fastly Compute WASM binaries locally and serves as the authoritative reference for Compute platform internals' plus a comprehensive concrete enumeration — 'host ABI, caching and purging APIs, KV/config/secret store interfaces, rate limiting with counters and penalty boxes, ACL lookups, the full request lifecycle, backend fetch semantics, and a built-in per-request profiler with hostcall spans, backend waterfalls, native CPU samples'. Multiple specific concrete capabilities cover the platform surface with no notable gaps, matching the 5 anchor.

Completeness

Explicitly answers both: what ('Runs Fastly Compute WASM binaries locally and serves as the authoritative reference for Compute platform internals...') and when ('Use when working with Compute runtime internals or host calls, understanding how edge data stores behave at runtime, profiling local Compute apps, or testing WASM binaries locally'). Concrete trigger phrases match the 5 anchor.

Trigger Term Quality

Good natural-term coverage — 'Fastly Compute', 'WASM binaries', 'host calls', 'profiling local Compute apps', 'edge data stores', 'non-Rust Compute work', 'Viceroy' — but a few natural variations are missing, notably 'Compute@Edge' (Fastly's official naming, present only in the body trigger section) and the '.wasm' file extension. This fits 'good keyword coverage; a few natural terms missing' rather than the 5 anchor's synonyms-and-extensions coverage.

Distinctiveness Conflict Risk

Clear niche — Fastly Compute local runtime and internals reference — with active conflict management ('Prefer this skill over Viceroy for any non-Rust Compute work'). Minimal risk of triggering for the wrong skill.