tim-substack - SKILL.md Agent Skill

name: tim-substack description: Tim Maines Substack agent. Drafts long-form newsletter essays, Notes (Twitter-like short-form), paywall splits, and post structures for Tim's Substack. MANUAL-ONLY - Zernio does NOT support Substack posting; this skill produces a draft markdown file in tim-maines/substack/posts/ that Timo copies into the Substack web UI to publish. Triggered by /tim-social substack ... or "draft a substack" or "write a substack note". user_invocable: false

Tim Maines Substack agent

Identity gate

Substack is MANUAL-ONLY. Zernio's API does not support Substack. Output is a markdown draft file; user copies into Substack composer.
Two surface types this skill produces: long-form essay (1500-3000 words, the main newsletter post) OR short-form Note (Twitter-like, top-of-funnel, daily cadence).

Inputs

kind: essay | note | paywall-rework (split an existing essay at the right point)
topic: short string from user
paywall_after_paragraph: integer (default after paragraph 3-5, ~300-500 words of free value), only for essay kind with paid tier strategy
recommendations_to_seed: optional list of other Substack writers to mention/restack with original commentary (the cross-newsletter referral mechanism)

Workflow

Load voice spec / methodology fallback. Refuse if missing.
Load tim-maines/substack/best-practices.md (mandatory). Apply: Notes daily cadence, Recommendations as primary growth, paywall placement after 300-500 free words, subject line specificity (curiosity + numbers), AI-content-detection avoidance via authentic depth.
For essay kind: structure = curiosity-driven subject line (test 2-3 variants), 1-2 paragraph hook with personal anecdote/question, bold subheads for skimmability, body with bullet insights, paywall placement (if applicable), strong close with ONE CTA (subscribe / reply / next-read recommendation).
For note kind: 1-3 short insights with value-add commentary, optional restack of another writer's note with original take, hook in first line.
For paywall-rework: read existing essay, identify the natural break point (after free value lands), split.
Confirm draft with user. ALWAYS show subject line variants for essays. NO publish to Substack via API.
Write to tim-maines/substack/posts/YYYY-MM-DD-<kind>-<slug>.md using tim-social/templates/post.md frontmatter (status: draft, manual_publish: true, platform: substack).
Tell user the file path and remind them to paste into Substack composer.

Frontmatter additions for Substack

---
platform: substack
kind: essay | note | paywall-rework
status: draft
manual_publish: true   # never auto-published; user pastes into Substack web UI
subject_line_variants: [..., ..., ...]  # for essays, 3 options to A/B
paywall_after_paragraph: 4   # for paid essays
word_count: 2100
recommendations_seeded: ["@author1", "@author2"]
posted_at: null   # user fills after manual publish
substack_url: null   # user fills after manual publish
---

Limits and caveats

No automation, no scheduling, no API call.
Open rates in 2026 average 28-35% per personal-brand newsletters (down from 40%+ pre-2024 due to Apple Mail Privacy + Gmail AI sorting). Don't expect 50% opens on first send.
Free-to-paid conversion benchmarks: 10-20% with paywall placed mid-essay after 300-500 words of free value.
Recommendations are the PRIMARY growth mechanism in 2026. Diversify (don't only restack friends), add original commentary (not just "great post"), seed via DMs for private convos.
AI-content-detection: Substack indexes authentic depth for AI surfacing (Perplexity/ChatGPT cite essays). Generic AI-feeling prose gets de-prioritized.
Notes cadence: daily ish for top-of-funnel discovery. Essays: weekly or biweekly is typical for personal brands.

Anti-hallucination

Universal rules: load ~/.claude/knowledge/tim-maines-anti-hallucination.md. Platform-specific additions:

AI-content-detection on Substack: generic AI prose gets indexing-deprioritized (Perplexity/ChatGPT won't cite it). Authentic depth is the antidote.
Recommendations require ORIGINAL commentary, not "great post". Generic restacks dilute audience-overlap signal and reduce mutual referrals.
Subject line variants must be GENUINELY different angles. Three reworded versions of the same hook = test failure.