Conciseness

The body is dense and nearly every sentence carries non-obvious, library-specific knowledge (unit mismatches, fetch limits, credential masking, join defaults). It falls short of 5 due to minor duplication and padding: the (×N) first-timestamp-only caveat is stated twice verbatim ("Gotchas" and "Read a web timeline"), and a few sentences (e.g. "A denial of some other command does not mean Bash is blocked") restate what a prior sentence implies. Not 3: the over-explanation is minor and localized, not a pattern.

Actionability

Fully executable, copy-paste-ready code with real method calls, parameter names, and expected outputs (e.g. `ws.replays_for_user("user-42", from_date=..., to_date=...)`, `print(bundle.top_clicks(10))`), plus exact CLI commands and self-documentation lookups (`mp help Workspace.replays_for_user`). The examples cover the common cases: fetch by user, by replay ID, correlate events, aggregate. Not 4: no gaps in concrete guidance.

Workflow Clarity

The numbered Workflow gives a clear sequence with explicit gates (check `replay.capture` before reading any timeline; read aggregates before timelines) and fallback branching (no distinct_id → find candidate users via mixpanelyst first), and the "Run code" section contains a full error-recovery loop (interpreter path fails → ask user to run setup → bare `mp --version` probe → version check before trusting lookups). Not 4: checkpoints and recovery paths are explicit, not implicit.

Progressive Disclosure

The SKILL.md is a working overview of the common web path, with exactly one clearly signaled, condition-gated, one-level-deep reference ([references/mobile.md](references/mobile.md), a real 128-line file) that is pointed to in two places (workflow step 2 and the closing section), plus an external tutorial via a single WebFetch URL. Mobile-specific detail is correctly split out. Not 4: the split and navigation are clean, with no inlined content that belongs in the reference.

Specificity

"Fetches a user's sessions, turns them into action timelines and pandas DataFrames, and explains what happened on screen" lists multiple specific concrete actions (fetch, timeline construction, DataFrame projection, on-screen explanation) with comprehensive coverage of the skill's surface. It does not fall to 4 because no meaningful capability gap exists: even event correlation is named.

Completeness

It explicitly answers both what ("Reads Mixpanel session replay recordings with the mixpanel_headless library…") and when ("Use when the user asks what a specific user did…"), with concrete trigger phrases and a complementary negative-scope clause ("Do not use for aggregate analytics…"). Not 4: the when-clause is fully explicit, not just present.

Trigger Term Quality

Natural user phrasing is covered comprehensively with synonyms and variants: "what a specific user did on screen, in a recording, or click by click", "rage clicks, dead clicks, rage taps, dead taps, error sessions, long pauses", plus identifiers ("distinct_id or a replay ID") and platform names ("iOS, Android, React Native, or Flutter"). Not 4: essentially no common variation is missing.

Distinctiveness Conflict Risk

A clear niche (individual session replay analysis) with distinct triggers, and explicit conflict-avoidance routing to adjacent skills: "use mixpanelyst" for aggregate analytics and "use dashboard-expert" for dashboards. Not 4: the negative triggers remove even the minor overlap risk with the closest neighboring skills.