4 min

Email & Calendar

Your First Useful Assistant

From Tools to Workflows

Having tools is one thing. Having an assistant that knows *when* and *how* to use them is another. This module turns your generic tool-calling assistant into a focused email and calendar productivity tool.

Email Triage: Teaching Claude Prioritization

The key to email triage is giving Claude explicit rules in the system prompt. Without rules, Claude makes reasonable but inconsistent decisions. With rules, every email gets classified the same way.

Priority	Criteria	Example
Critical	System alerts, production issues, time-sensitive deadlines	"Server down — all APIs failing"
Action Required	Requests that need a response or decision	"Can you review the Q3 proposal by Friday?"
FYI	Updates, newsletters, CC'd threads	"Team standup notes from Monday"
Low Priority	Marketing, social notifications, automated reports	"Your weekly analytics digest"

These rules go into the system prompt so Claude applies them consistently across all emails.

Morning Briefing Pattern

One of the most useful assistant features: a morning summary of everything that needs attention.

The pattern:

Call read_emails with status: "unread"

Call check_calendar for today's events

Claude synthesizes both into a structured briefing

A good briefing answers three questions:

What's urgent? — Emails needing immediate attention

What's my schedule? — Today's meetings with context

What can wait? — Lower-priority items to handle later

Calendar Awareness

Calendar queries fall into three categories:

Query Type	Example	What Claude Needs
Schedule overview	"What's my day look like?"	All events for the date
Availability check	"Am I free at 2pm?"	Events overlapping the time
People search	"When do I meet with Sarah?"	Events filtered by attendee

For availability checks, Claude needs to understand duration — a meeting from 1:00-2:30 means you're NOT free at 2pm.

Combining Email + Calendar

The real power comes from cross-referencing:

"Sarah emailed about rescheduling — when are we meeting next?" → search emails for Sarah + check calendar for Sarah

"I need to respond to the Globex proposal before my 3pm meeting" → find the Globex email + check what's at 3pm

"Cancel my afternoon and focus on the urgent emails" → list afternoon meetings + prioritize unread emails

This is where tool chaining shines. Claude calls multiple tools in sequence, using results from one to inform the next.

Drafting Replies

A good email reply assistant needs context:

The original email (subject, sender, body)

The user's relationship to the sender (from contacts)

The user's schedule (from calendar)

The user's communication style (from preferences)

The system prompt should specify reply guidelines:

Match formality to the incoming email

Keep replies concise — 3-4 sentences max

Include specific next steps when relevant

Never commit to times without checking the calendar

System Prompt Structure for Email + Calendar

A well-structured assistant system prompt has sections:

Role — "You are a personal executive assistant"

Triage Rules — Priority classification criteria

Reply Guidelines — Tone, length, what to include

Calendar Rules — How to handle availability, conflicts

Personality — Professional but warm, concise, proactive

Key Takeaways

Email triage needs explicit rules in the system prompt — don't let Claude guess priorities.

Morning briefings combine email + calendar data into actionable summaries.

Cross-referencing data sources (email senders + calendar attendees) creates compound value.

Draft replies should consider context: sender relationship, calendar, and communication style.

This is chapter 3 of Build Your AI Assistant with Claude.

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Ch. 2: Tool Use

Ch. 4: Research Agent