Domain 1 of 6 · Chapter 3 of 4

Use GitHub Copilot Features and Capabilities

Unlock the complete study guide.

Bundled into the existing GitHub Copilot premium course — no separate purchase.

14-day money-back guarantee — no questions asked.

Included in this chapter:

  • Capabilities by job: change, delegate, extend, review, converse
  • Changing code: edit mode, agent mode, and plan mode
  • What agent mode's self-correction does not prove
  • Agent sessions: the unit of delegated work
  • Sub-agents: delegating inside a session
  • Copilot cloud agent: background work on GitHub
  • MCP servers: tools and data beyond the editor
  • Agent Plugins: one package for skills and MCP configuration
  • Copilot Spaces: reusable, shareable grounding context
  • Copilot code review: when it runs and what it counts for
  • Review standards: instruction files and AGENTS.md
  • Pull request summaries: a draft for reviewers
  • Copilot Chat: models, commands, feedback, and limits
  • Prompt files: reusable prompts invoked on demand
  • GitHub Spark: a retired app-building surface
  • Reading exam scenarios: cues and tempting wrong answers

Copilot capabilities by job: where each runs and who drives the steps

CapabilityJobWhere it runsWho drives the stepsCommonly confused with
Edit modeChange codeJetBrains IDEs; deprecated in VS Code 1.126You choose the working set and accept or discard each turnAgent mode
Agent modeChange codeIDE, in your local environmentCopilot picks files, commands, and iterationsCopilot cloud agent
Plan modeChange codeIDE, read-only researchCopilot drafts a plan; nothing changes until you approveAgent mode
Sub-agentDelegate workInside a Chat session, in its own context windowThe main agent or you route a task to it; it returns only its resultA second chat you must read in full
Copilot cloud agentDelegate workGitHub, in a GitHub Actions-powered environmentCopilot researches, plans, and commits to a branch in the backgroundIDE agent mode
MCP serverExtend and groundAny Copilot surface that connects itIn an IDE, agent mode calls the tools you enabled; confirmation may be requiredCopilot Space
Agent PluginExtend and groundVS Code, Copilot CLI, GitHub Copilot SDK, GitHub Copilot appOne package carries skills and MCP configurationManual per-client configuration
Copilot SpaceExtend and groundCopilot Chat in GitHub; IDE through the GitHub MCP serverYou curate the sources; Chat answers from themA local workspace folder
Copilot code reviewReview changesPull requests on GitHub.com, IDEs, and other clientsCopilot comments and suggests fixes; by default, people approvePull request summary
Pull request summaryReview changesPull request description or comment on GitHub.comCopilot drafts; the author edits and publishesCopilot code review
Instruction files and AGENTS.mdReview changesRepository files, read from the head branchApplied automaticallyPrompt file
Prompt fileConverse and reuseVS Code, Visual Studio, JetBrains IDEsYou invoke it on demandCustom instructions
GitHub SparkRetired app builderAccess ended August 31, 2026Not available for new appsGitHub Copilot app

Decision tree

Does the taskchange code?YesNoRun in the backgroundon GitHub?YesCopilot cloud agentNoRequirementsstill open?YesPlan modeNoWant to choosethe files yourself?YesEdit mode(JetBrains IDEs)VS Code: edit modedeprecated (1.126);agent mode instead,Copilot picks filesNoAgent modeFind issues in apull request?YesCopilot code reviewNoOrient reviewers onwhat changed?YesPull request summaryNoContext must persistand be shared?YesCopilot SpaceNoNeed a liveexternal system?YesMCP server(in IDE agent mode)NoCopilot Chat withfocused context
Cheat sheet

Cheat sheet

  • Copilot Edits applies a requested change across multiple files
  • Agent mode autonomously chooses implementation steps and relevant files
  • Plan mode separates read-only planning from implementation
  • Agent mode can iterate on failures but cannot certify its own correctness
  • MCP servers extend Copilot with external data sources and actions
  • Agent mode can discover and invoke enabled MCP tools
  • Organization policy can govern MCP use in Copilot surfaces
  • An MCP server must be trusted for both the data and tools it exposes
  • Agent Plugins package reusable skills and MCP configuration for compatible Copilot clients
  • An agent task runs in a session that can be tracked and steered
  • A sub-agent performs delegated work in an isolated context window
  • Sub-agent delegation can be automatic or explicitly requested
  • By default, sub-agents return results rather than creating nested sub-agents
  • Copilot cloud agent performs asynchronous repository work in a GitHub-hosted environment
  • Copilot code review identifies issues and proposes applicable fixes
  • Copilot reviews are requested manually unless automatic review is configured
  • A default Copilot review comment does not satisfy required approval
  • Review effort should match the complexity and sensitivity of the change
  • Copilot code review uses its own model mix rather than the Chat model picker
  • A new push is not re-reviewed unless that trigger is configured or requested
  • Copilot Spaces organize reusable context for grounded conversations
  • GitHub-based sources in a Space stay synchronized as they change
  • Sharing a Space does not grant access to its restricted sources
  • Spaces are used in GitHub Chat and can reach an IDE through the GitHub MCP server
  • GitHub-backed sources in a Copilot Space stay synchronized
  • GitHub Spark was a natural-language full-stack application builder
  • GitHub Spark is no longer a current choice for creating a new app
  • A pull request summary drafts an overview of changes for reviewers
  • A generated pull request summary remains an editable draft
  • Pull request summaries can be incomplete or inaccurate and require validation
  • Repository-wide Copilot review standards belong in the Copilot instructions file
  • Path-specific review standards belong in scoped instructions files
  • AGENTS.md provides standing repository rules across compatible agents
  • Code review reads customization from the pull request head branch
  • Available Chat models depend on the surface, plan, and organization policy
  • Chat responses are constrained by available context and can be wrong
  • Chat commands and participants vary by host and active context
  • Response feedback reports quality but does not directly correct the active answer
  • Prompt files encode reusable prompts for tasks invoked on demand
  • Workspace prompt files make a repeatable interaction versionable and shareable
  • Prompt files and custom instructions solve different reuse problems
  • Prompt-file support must be checked for the target IDE

Unlock with Premium — includes all practice exams and the complete study guide.

Also tested in

References

  1. https://code.visualstudio.com/updates/v1_126
  2. https://docs.github.com/en/copilot/how-tos/chat-with-copilot/chat-in-ide
  3. https://docs.github.com/en/copilot/concepts/agents/cloud-agent/about-cloud-agent
  4. https://docs.github.com/en/copilot/concepts/agents/code-review
  5. https://learn.microsoft.com/en-us/credentials/certifications/resources/study-guides/gh-300
  6. https://docs.github.com/en/copilot/concepts/context/spaces
  7. https://docs.github.com/en/copilot/how-tos/chat-with-copilot/chat-in-ide?tool=jetbrains
  8. https://docs.github.com/en/copilot/tutorials/review-ai-generated-code
  9. https://docs.github.com/en/copilot/how-tos/copilot-on-github/use-copilot-agents/manage-and-track-agents
  10. https://docs.github.com/en/copilot/concepts/context/mcp
  11. https://modelcontextprotocol.io/docs/getting-started/intro
  12. https://modelcontextprotocol.io/docs/learn/architecture
  13. https://docs.github.com/en/copilot/responsible-use/agents
  14. https://docs.github.com/en/copilot/how-tos/provide-context/use-mcp-in-your-ide/extend-copilot-chat-with-mcp
  15. https://docs.github.com/en/copilot/how-tos/administer-copilot/manage-for-organization/manage-policies
  16. https://code.visualstudio.com/docs/agent-customization/mcp-servers
  17. https://github.blog/changelog/2026-08-12-agent-plugins-1-0-in-vs-code-copilot-cli-and-the-copilot-app/
  18. https://docs.github.com/en/copilot/concepts/agents/about-agent-skills
  19. https://docs.github.com/en/codespaces/about-codespaces/what-are-codespaces
  20. https://docs.github.com/en/copilot/how-tos/use-copilot-agents/request-a-code-review/use-code-review
  21. https://docs.github.com/en/copilot/how-tos/copilot-on-github/set-up-copilot/configure-code-review
  22. https://docs.github.com/en/copilot/how-tos/copilot-on-github/customize-copilot/add-custom-instructions/add-repository-instructions
  23. https://docs.github.com/en/copilot/concepts/prompting/response-customization
  24. https://docs.github.com/en/copilot/how-tos/copilot-on-github/copilot-for-github-tasks/create-a-pr-summary
  25. https://docs.github.com/en/copilot/responsible-use/chat
  26. https://docs.github.com/en/copilot/responsible-use/pull-request-summaries
  27. https://docs.github.com/en/copilot/how-tos/use-ai-models/change-the-chat-model
  28. https://docs.github.com/en/copilot/reference/chat-cheat-sheet
  29. https://docs.github.com/en/copilot/tutorials/customization-library/prompt-files/review-code
  30. https://code.visualstudio.com/docs/agents/concepts/agent-host
  31. https://code.visualstudio.com/api/advanced-topics/extension-host
  32. https://github.blog/changelog/2025-07-23-github-spark-in-public-preview-for-copilot-pro-subscribers/
  33. https://github.blog/changelog/2026-08-04-upcoming-deprecation-of-github-spark-on-github-com/