Microsoft 365 Copilot Extension Patterns

This skill provides rules for building reliable Microsoft 365 Copilot extensions. Rules are ordered by impact: CRITICAL rules prevent broken extensions or security issues; HIGH rules prevent common development mistakes; MEDIUM rules improve user experience and maintainability.

Learned Patterns (Auto-Updated)

Before applying the rules below, check if LESSONS.md exists in the project root. If it does, read the section tagged with m365-copilot-extensions and apply those project-specific lessons alongside the rules below.

Category 1: Declarative Agents (CRITICAL)

Rule 1: Declarative Agent Manifest Structure

Impact: CRITICAL — Malformed manifests cause silent deployment failures in Teams Admin Center.

❌ Wrong: