Add engine comparison table to engines documentation

[Copilot]

Users lack visibility into feature parity across engines, making it difficult to choose between Copilot CLI, Claude, and Codex for their workflows.

Changes

• Engine Comparison Table: Added feature matrix comparing workflow triggers, GitHub tools, safe outputs, custom MCP servers, web search capabilities, agent sessions, bot assignments, and setup complexity
• Feature Parity Callout: Added tip clarifying 95%+ feature compatibility across all engines, with only agent sessions and bot assignments requiring Copilot

Key Findings

• Agent sessions (create-agent-session) and bot assignments (assign-to-agent) are Copilot-exclusive features
• Claude has built-in web search; Copilot and Codex require Tavily MCP server
• All other features (triggers, safe outputs, MCP servers, GitHub tools) work identically

Screenshot

Original prompt

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This section details on the original issue you should resolve

<issue_title>[plan] Add engine comparison table to engines.md</issue_title>
<issue_description>## Context

As identified in discussion #12027, users lack a clear comparison between engines to make informed decisions. The current documentation explains each engine separately but never compares them directly.

Problem

• Claude Code users want to know "what am I giving up by not using Copilot?"
• No table showing feature parity across engines
• No guidance on "when to choose X vs Y"
• Users cannot easily assess which engine fits their needs

Objective

Add a comprehensive engine comparison table and "when to choose" guidance to help users select the appropriate engine.

Proposed Solution

Add to docs/src/content/docs/reference/engines.md after the introduction:

## Engine Comparison

| Feature | Copilot CLI | Claude | Codex |
|---------|-------------|--------|-------|
| All workflow triggers | ✅ | ✅ | ✅ |
| GitHub tools & MCP | ✅ | ✅ | ✅ |
| Safe outputs | ✅ | ✅ | ✅ |
| Custom MCP servers | ✅ | ✅ | ✅ |
| Web search (MCP) | ⚠️ Tavily MCP | ✅ Built-in + MCP | ⚠️ Tavily MCP |
| Agent sessions | ✅ | ❌ | ❌ |
| Bot assignments | ✅ | ❌ | ❌ |
| Setup complexity | PAT required | API key | API key |

### When to Choose

- **Claude**: Best for general-purpose automation, excellent reasoning, simple API key setup
- **Copilot**: Best when you need agent sessions or Copilot bot assignments
- **Codex**: Alternative OpenAI-based option for API-based workflows

> [!TIP]
> 95%+ of features work identically across all engines. Only Copilot-specific features (agent sessions, bot assignments) require Copilot.

Files to Modify

• docs/src/content/docs/reference/engines.md

Acceptance Criteria

• Add comparison table showing feature parity
• Add "When to Choose" section with clear guidance
• Add tip callout about 95%+ feature parity
• Verify table renders correctly in documentation site
• Ensure accuracy of feature comparison (based on current codebase)

References

• Discussion 🔍 Claude Code User Documentation Review - January 27, 2026 #12027 - Priority 1 recommendation (Major Obstacle 2)

AI generated by Plan Command for discussion #12027

Comments on the Issue (you are @copilot in this section)

• Fixes [plan] Add engine comparison table to engines.md #12032

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[pelikhan]

@copilot remove section

[Copilot]

Removed the "When to Choose" section in commit f248457.

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /opt/hostedtoolcache/node/24.13.0/x64/bin/node node /home/REDACTED/work/gh-aw/gh-aw/docs/node_modules/.bin/astro build (dns block)
  • Triggering command: /opt/hostedtoolcache/node/24.13.0/x64/bin/node node /home/REDACTED/work/gh-aw/gh-aw/docs/node_modules/.bin/astro preview (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)