Conciseness

The body is dense with non-obvious, CLI-specific gotchas (unintuitive command paths, boolean-flag behavior, propagation delays, KV eventual consistency) and assumes Claude's competence — no padding explaining what a CDN or TLS is. It falls short of 5 due to redundancy: version-targeting flags are listed in both 'Global Flags' and 'Key Patterns', the 'Logging is under `service logging`' note duplicates the opening CRITICAL line, and `fastly service domain/backend create` examples appear in both 'Common Flag Examples' and the new-service workflow.

Actionability

Fully executable, copy-paste-ready commands throughout: correct/wrong flag contrasts ('CORRECT - boolean flags are bare, no value' vs the WRONG variant), complete backend create invocations with all four TLS flags, jq fallback selectors ('.ActiveVersion.Number // .ActiveVersion'), and curl/openssl pre-flight checks. Specific examples cover the common cases and the highest-confusion flags.

Workflow Clarity

The 'New VCL Service Setup Workflow' is a 6-step sequence with an explicit validation checkpoint at nearly every step — TLS SAN pre-flight check, `fastly service version validate` before activation, and post-activation verification with error-recovery guidance ('If 500 "Domain Not Found", wait and retry... If 503, check backend SSL settings'). This matches the anchor's validate -> fix -> retry feedback-loop pattern; no gaps to justify 4.

Progressive Disclosure

A clear overview structure with a well-signaled references table of 10 one-level-deep files (all verified to exist), each with a 'Use when...' column for discovery, plus a dedicated troubleshooting.md link. Content is appropriately split: command structure, top pitfalls, and one worked workflow inline; provider-specific detail (25+ logging providers, NGWAF workspaces, TLS subscriptions) lives in the reference files. Below-5 would require buried references or inline content that belongs in the bundle, neither of which applies.

Specificity

Lists many concrete actions — 'managing CDN services, Compute deploys', 'managing backends/domains/VCL snippets', 'purging cache', 'configuring log streaming', 'setting up TLS certificates', 'managing KV/config/secret stores', 'authenticating with Fastly SSO', 'working with fastly.toml', plus 'service CRUD, version management, autocloning, and troubleshooting common CLI errors'. Coverage is comprehensive across the CLI's surface; not below 4 because there are no meaningful gaps in the action list.

Completeness

Explicitly answers both: what ('Executes Fastly CLI commands for managing CDN services, Compute deploys, and edge infrastructure') and when ('Use when running `fastly` CLI commands, creating or managing Fastly services from the terminal, ...'), followed by a second explicit trigger clause ('Also applies when working with Fastly service IDs in CLI context...'). This mirrors the anchor-5 example structure of what + 'Use when' with concrete triggers.

Trigger Term Quality

Natural user phrasing is comprehensively covered with synonyms and specifics: 'running `fastly` CLI commands', 'from the terminal', 'via command line', 'deploying Fastly Compute applications', 'purging cache', 'fastly.toml', 'Fastly service IDs', and exact subcommand names ('`fastly service`, `fastly compute`, `fastly auth`, or any Fastly CLI subcommand'). Matches the anchor's 'synonyms and file extensions' bar; score 4 would require noticeably missing natural terms, which is not the case.

Distinctiveness Conflict Risk

A clear niche — the Fastly CLI — with distinct triggers (`fastly` binary, fastly.toml, named subcommands, 'in CLI context'). It explicitly scopes stats and service-ID work to the CLI context, minimizing collision with adjacent Fastly skills; no generic language that would fire for unrelated skills.