Conciseness

The ~470-line body is noticeably verbose: platform information is repeated four times (the architecture diagram, Platform Support table, Architecture list, and Technical Details), there are two separate 'Best Practices' sections, 'Common Patterns' restates the earlier command examples, and Technical Details explains implementation internals (JXA via osascript, BSD date flags, PowerShell [DateTime]::Parse) that Claude neither needs nor is even told to inspect. It is above 1 because the operational sections themselves (commands, output format, error codes) are information-dense rather than padded with concepts Claude already knows.

Actionability

Every operation (list, create, update, delete, search) has complete, copy-paste-ready bash commands with all flags shown, the script path construction is spelled out step-by-step with a worked example, and the JSON success/error response shapes plus an error-code table with recoverability flags give fully executable guidance. Specific examples cover the common cases (date ranges, calendar selection, notes/location, searching by keyword), matching the 'fully executable, copy-paste ready' anchor.

Workflow Clarity

Sequences are clear and checkpointed for the risky operations: 'Always Check Before Creating' (list before create), 'Search Before Updating/Deleting' (find the event ID first), an error-handling pattern that parses the response and branches, and Troubleshooting entries that pair each error with a concrete solution — a feedback loop. It falls short of 5 because there is no explicit confirm-before-delete step for the destructive delete operation and validation relies on the model reading JSON output rather than an explicit checkpoint instruction.

Progressive Disclosure

Scored against the actual bundle: both referenced scripts (scripts/calendar.sh, scripts/calendar.ps1) exist and their paths are clearly signaled with explicit path-construction instructions — good one-level-deep tool disclosure. However, the SKILL.md itself is monolithic: Troubleshooting, Known Behaviors, Technical Details, and the full Error Codes/JSON reference are all inlined (~470 lines) where they clearly belong in reference files, so structure exists but content that should be separate is inline.

Specificity

The description names the domain ("Calendar on macOS and Windows") but its actions are generic — "Access local system resources" and "manage user's schedule" — with no concrete operations (view, create, update, delete events) named, matching the 'names the domain but actions are minimal or generic' anchor. It does not reach 3 because no concrete action verb is ever specified; the mild second-person trigger phrasing ('when you need to manage') also works against the third-person voice the rubric rewards.

Completeness

Both parts are present: a what ("Access local system resources including Calendar on macOS and Windows") and an explicit when ("Use this skill when you need to manage user's schedule directly on their device"), so the missing-'Use when' cap at 3 does not apply. It falls short of 5 because the 'what' is vague (no operations listed) and the 'when' lacks concrete trigger phrases like 'show me my schedule' or 'create a meeting'.

Trigger Term Quality

It includes the two most natural user phrasings — "Calendar" and "manage user's schedule" — plus platform terms (macOS, Windows), giving good keyword coverage. It stays below 5 because common variations users actually say — "events", "meetings", "appointments", "my calendar today" — are missing, and "local system resources" is technical jargon rather than a natural trigger.

Distinctiveness Conflict Risk

"Calendar on macOS and Windows" and "manage user's schedule directly on their device" carve out a fairly clear local-calendar niche with distinct triggers. It is not 5 because 'local system resources' is broad and could overlap with other local-device or scheduling-related skills (e.g. email-based invitation tools), and no disambiguating contrast is drawn.