Conciseness

The body is dense, operational edge-case guidance that assumes Claude's competence (no concept padding), but the Guardrails section restates rules already given in steps 3-4 ("Use only artifactPaths.specs.existingOutputPaths; never infer...", "Honor a caller-supplied subset... never widen it back to the full list") and "Never write an empty ## Requirements section" appears twice, so minor trimming is possible.

Actionability

Provides fully executable commands (openspec status --change "<name>" --json, openspec list --json, openspec instructions specs --change "<name>" --json, openspec validate --specs), exact JSON fields to read (planningHome.root, artifactPaths.specs.existingOutputPaths), exact file paths, copy-paste format templates, and a concrete success-output template covering the common cases.

Workflow Clarity

Six clearly sequenced steps with an explicit validation checkpoint (step 5: run openspec validate --specs and do not claim success on failure) and extensive pre-write gates (root check, "Declared in" error branch, stop on non-zero/invalid instructions JSON, six retirement conditions), giving every risky write an explicit check.

Progressive Disclosure

A single-file skill (no references/, scripts/, or assets/ exist) with well-organized, clearly headed sections (Steps, Delta/Main Spec Format References, Key Principle, Output, Guardrails); the format references are used mid-workflow so inline placement is defensible, but at ~280 lines the store-selection and retirement digressions could live in referenced files.

Specificity

States one concrete action ("Sync delta specs from an OpenSpec change to main specs") with a distinguishing qualifier ("without archiving the change"), but does not list several distinct capabilities, matching the '1-2 concrete actions, not comprehensive' anchor rather than the multi-action anchor 4.

Completeness

Explicitly answers both what ("Sync delta specs from an OpenSpec change to main specs") and when ("Use when the user wants to update main specs... Also use when the user says \"openspec sync\" or \"opsx sync\"") with concrete trigger phrases, matching the top anchor.

Trigger Term Quality

Includes the exact command phrases users would naturally say ("openspec sync", "opsx sync") alongside natural phrasings like "update main specs" and "delta spec", giving comprehensive trigger coverage for this niche with no obviously missing variation.

Distinctiveness Conflict Risk

Clear niche (OpenSpec delta-to-main spec sync) explicitly distinguished from archiving ("without archiving the change") with distinct command triggers, so conflict risk with other skills is minimal.