Conciseness

Nearly every line carries project-specific, non-obvious content (e.g. "Sending the hidden credential into the space as a search pattern invalidates that proof", "Completed client handshakes alone do not prove the server accepted the connections") with no padding or explanation of concepts Claude already knows. Not 5 because several long compound sentences and repeated phrasing of the owning-contract path could be tightened without losing meaning.

Actionability

Guidance is concrete and directive for an instruction-only skill: a routing table mapping each change type to specific documentation sections, named sibling skills per concern, and exact test controls (alternative address spellings, small test caps with server-acceptance checks, journal assertions independent of cross-process clock precision). Not 5 because no executable commands or examples are given for steps like running the test suites or building the disposable copy; the skill delegates those to DOCUMENTATION.md.

Workflow Clarity

The sequence is explicit with strong validation checkpoints and feedback loops: read the owning contract, load branch context, trace each guarantee (with an explicit completion criterion), then the three-step proof loop — make the regression discriminate, remove the protection and "watch it go red", restore it and "watch it go green" — plus separate completion criteria and reporting rules. This matches the anchor with explicit validation, error-recovery checks (setup error vs. promised violation, independent blocking protection), and checklists.

Progressive Disclosure

A compact single-file skill (~60 lines) with clear section headers (Read The Owning Contract, Trace The Guarantee, Prove The Protection, Completion) and a scannable routing table, delegating all detail to one clearly signaled, one-level-deep external reference (packages/web/server/lib/spaces/DOCUMENTATION.md) and named sibling skills. No bundle files exist to inline or misorganize, and navigation is easy, matching the well-organized anchor rather than the minor-gaps anchor below.

Specificity

"container hardening, networks and gatekeeper policy, exec and lifecycle, grants and credentials, code transfer and apply, dispatcher isolation, preview content" enumerates many concrete, specific change areas rather than vague language. Not 5 because the items are application scopes rather than distinct capability actions (no verb beyond 'changing' states what the skill does); not 3 because coverage of the domain is far broader and more concrete than the 1-2-action anchor.

Completeness

The 'when' is explicit and strong ("Use when changing isolated-space trust boundaries... or tests of these protections"), but no 'what' is stated — the skill's actual capability (guiding enforcement changes and their evidence) is only implied by the trigger list. Not 2 because the highly specific when-clause makes the subject matter clear; not 4 because scoring only what is explicit, no capability statement is present.

Trigger Term Quality

Terms like "container hardening", "networks", "gatekeeper policy", "exec", "grants and credentials", "dispatcher isolation", "preview content" are exactly what a developer on this codebase would say when the skill applies. Not 5 because no synonyms or phrasing variations are included (e.g. sandbox, isolation, hardening tests), so a few natural trigger phrasings could be missed.

Distinctiveness Conflict Risk

"isolated-space trust boundaries" scopes every listed trigger to a clear niche with distinct triggers (gatekeeper policy, corridor/window, space credentials, dispatcher isolation), minimizing conflict with generic container, network, or testing skills. It matches the 'clear niche with distinct triggers; minimal conflict risk' anchor rather than the minor-overlap anchor below, since even broad terms like 'tests' are qualified by 'of these protections'.