Conciseness

The body is mostly efficient, but the Guardrails section repeats rules already stated in the steps ("Always prompt for change selection if not provided", "Show clear summary of what happened", "If delta specs exist, always run the sync assessment and show the combined summary before prompting"), and phrases like "Parse the JSON to understand" pad slightly. This matches anchor 3 ('mostly efficient but includes some unnecessary explanation or could be tightened') rather than anchor 4, where redundancy would be only minor.

Actionability

Guidance is mostly executable: concrete commands (`openspec list --json`, `openspec status --change "<name>" --json`, `mkdir -p openspec/changes/archive`, `mv openspec/changes/<name> ...`), exact paths, JSON fields to parse, prompt option labels, and an output template. Minor gaps keep it from anchor 5: no concrete way to generate the date (e.g. `date +%F`), the tasks file is only "typically `tasks.md`" without its full path, and the exists-check lacks a concrete test command.

Workflow Clarity

Six clearly sequenced steps with explicit validation checkpoints throughout: artifact status check, incomplete-task count check, and a pre-move exists-check with a defined error path ("If yes: Fail with error, suggest renaming existing archive or using different date"). User confirmations gate every warning, and the destructive `mv` is guarded by these checks, so the destructive-operation cap does not apply and the content matches anchor 5 (clear sequence, explicit validation, error-recovery paths).

Progressive Disclosure

The skill has no bundle files (references/, scripts/, assets/ are absent) and is a single self-contained file, well-sectioned into Input, Steps, Output On Success, and Guardrails, with the one cross-skill delegation (openspec-sync-specs via the Task tool) clearly signaled. At ~115 lines it exceeds the under-50-lines threshold for a default 5, and the Guardrails section could be trimmed or moved, so anchor 4 ('good structure; most content appropriately placed; minor organization gaps') is the best fit.

Specificity

The description names the domain and one concrete action ("Archive a completed change") but does not enumerate what the skill actually does (verify task/artifact completion, sync delta specs, move to archive). This matches anchor 3 ('names domain and 1-2 concrete actions, but not comprehensive') and falls short of anchor 4, which expects several specific listed actions.

Completeness

Both "what" ("Archive a completed change in the experimental workflow") and "when" ("Use when the user wants to finalize and archive a change after implementation is complete") are explicitly present. However, the "when" clause largely restates the "what" rather than adding distinct concrete trigger phrases, so it matches anchor 4 rather than anchor 5.

Trigger Term Quality

Relevant keywords are present ("archive", "finalize", "implementation is complete") but common natural variations a user would say are missing ("done", "move to archive", "wrap up the change", "completed change"). This fits anchor 3 ('some relevant keywords but missing common variations or synonyms') better than anchor 4's 'good keyword coverage'.

Distinctiveness Conflict Risk

"completed change" and "the experimental workflow" carve out a niche, but "archive a change" is generic enough to overlap with other archive/cleanup or openspec lifecycle skills (e.g., sync-specs, other finalize workflows). This is anchor 3 ('somewhat specific but could still overlap with similar skills'), not anchor 4's 'mostly distinct'.