Conciseness

The body is lean, bullet-dense, and assumes Claude's competence — it never explains what Slack is or basic concepts, and every section adds operational knowledge (RPM buckets, backoff timings, DM routing) that Claude would not already know.

Actionability

Though code-free, the instruction-only guidance is highly concrete and specific — "wait about 30 seconds", "Treat slack_search_* tools as the search bucket", "prefer [an existing group DM] over duplicate one-to-one DMs" — so the absence of code is not penalized.

Workflow Clarity

The Overview gives a clear read → route → (switch to slack-outgoing-message before writes) sequence, and there are explicit validation/checkpoint steps (support checks, re-read-before-write on relative targets, a 429 backoff feedback loop).

Progressive Disclosure

A clear overview routes to sibling skills and a single well-signaled, one-level-deep reference (references/markdown.md, verified to exist) via the Reference Notes table; formatting detail is appropriately split out rather than inlined.

Specificity

Lists three concrete actions — "Read Slack context", "route to the right Slack workflow", and "prepare or perform Slack writes" — matching the multi-action score-3 anchor rather than the single-domain score-2 anchor.

Completeness

It clearly answers what the skill does, but there is no "Use when..." clause or equivalent explicit trigger, so per the judging guidelines completeness is capped at 2.

Trigger Term Quality

The core keyword "Slack" recurs, but phrases like "Slack writes" and "Slack workflow" are internal jargon rather than natural user phrasings, and common variations ("send/draft/post a Slack message", "summarize a channel") are absent.

Distinctiveness Conflict Risk

"Slack" is a clear niche and the "route to the right Slack workflow" framing explicitly signals the router role, making it unlikely to trigger for a non-Slack skill.