GitHub Copilot

Copilot supports repository-wide, path-specific, and agent instruction files; exact file support varies by product surface.

GitHub documents instruction support on selected web experiences, but supported file types and behavior vary by feature.

Copilot documents lifecycle hooks and decision control, but hook timeouts fail open; use them as automation and guardrails, not a universal hard-policy boundary.

The reviewed hooks source does not establish the same event and decision contract for general IDE and web interactions.

Copilot documents Agent Skills for specialized instructions, scripts, and resources, with product-specific discovery and precedence.

The reviewed CLI sources are insufficient to classify skill discovery and invocation on IDE and web surfaces.

Copilot documents custom agents with isolated context and role-specific tools, used as subagents by the primary agent.

The reviewed CLI customization sources do not establish one equivalent custom-agent contract for IDE and web surfaces.

Copilot CLI Fleet decomposes work across parallel subagents and documents sibling-agent discovery and messaging.

Fleet is documented for Copilot CLI; the reviewed sources do not establish the same team topology on IDE, web, or cloud surfaces.

Copilot CLI provides first-party MCP server configuration and management.

Copilot cloud agent supports MCP tools, but the documented surface excludes resources, prompts, and remote OAuth.

The reviewed CLI and cloud sources are insufficient to classify the remaining IDE and web MCP surfaces as equivalent.

Copilot CLI provides built-in slash commands plus command files as a simplified, lower-priority alternative to skills.

The reviewed command reference is CLI-specific and does not establish identical commands elsewhere in the Copilot family.

Copilot CLI provides personal settings, permissions, provider, extension, and agent customization controls.

The reviewed CLI settings source is insufficient to define one equivalent configuration contract across the wider Copilot family.

Copilot CLI documents a memory tool and explicit memory enablement controls for prompt-mode sessions.

The reviewed CLI source is insufficient to assert one shared memory contract across Copilot's editor, web, and cloud surfaces.