Problem

Meeting-prep (and other automated) Slack messages still render with bad formatting even though the "universal Slack styling" fix (#2359) is live. Root cause is a Markdown-dialect mismatch, not a missing deploy.

• #2359's renderer (markdown-to-slack-richtext.ts) parses message bodies as standard Markdown: **x** → bold, and a single *x* → italic (regex m[15]). There is no mrkdwn→Markdown normalization step.
• But agents were still told to use Slack mrkdwn (*bold*, •). So every section label an agent wrote as *Open Commitments* / *Top priorities:* rendered italic, and long prep briefs looked broken.

Verified against real runs on <email> (Dynasty / Hey Telo meeting-prep, Aug 21): the delivered notify-user bodies contain single-asterisk labels and literal • bullets.

This same trap was already fixed in notifications/SKILL.md and agent-defaults/pipeline-review.ts (which explicitly says use **bold**, "a real header block , not *italic*", "never the literal •"). This PR propagates that contract to the sources that were missed.

Fix

The decisive gap: the notify-user / send-slack tool descriptions had no markup guidance at all , text was just "Sent to all configured notification channels", and send-slack even claimed "converted to Slack mrkdwn automatically." That tool schema is the guidance every automated agent sees at the point of use, regardless of which skill it loaded , so it's the lever that actually reaches meeting-prep / daily-agenda.

• notify-user: text and threadReplies[].text now state the Markdown contract (**bold** not *bold*; - bullets never •; ### headers).
• send-slack: corrected the misleading message description.
• drafting/slack.md: **bold**, - bullets (never •), ### headers , was *bold* / - or •.
• drafting-content.ts: the Slack side of the channel-format rule matches the above (email/HTML side unchanged).

Why guidance-only (no converter change)

*x* is legitimately italic in Markdown, so teaching the converter to treat single-asterisk as bold would break real italics. The house contract (per the converter, notifications/SKILL.md, and pipeline-review.ts) is "standard Markdown" , this aligns the remaining guidance to it.

Note / follow-up

LLMs have a strong "Slack bold = *x*" prior, so guidance raises adherence but may not be a 100% guarantee. If a specific agent (e.g. a customized meeting-prep subagent) keeps drifting, the belt-and-suspenders is to make that subagent's own Notify step explicit , a per-account playbook edit, out of scope here.

Test plan

• Trigger a meeting-prep run; confirm section labels render bold (not italic) and bullets are native rich_text.
• Confirm a drafted Slack follow-up (draft-slack) uses **bold** / -.

🤖 Generated with Claude Code

Greptile Summary

This PR aligns Slack-facing agent instructions and notification tool schemas with Cedar’s standard-Markdown-to-rich-text renderer.

• Replaces Slack mrkdwn guidance with **bold**, - bullets, and ### headings.
• Updates notify-user, thread-reply, and send-slack parameter descriptions.
• Leaves a cross-channel mismatch because shared notify-user.text is also delivered to WhatsApp without equivalent Markdown normalization.

Confidence Score: 4/5

The cross-channel notify-user guidance should be fixed before merging because WhatsApp recipients can receive raw standard-Markdown markers.

The new formatting contract is correct for Slack and normalized for iMessage, but the shared notification text reaches WhatsApp without converting or stripping the newly mandated emphasis and heading syntax.

Files Needing Attention: apps/server/src/mastra/tools/notify/notifyUserTool.ts

Important Files Changed