generalize /init skill to also suggest other chat customizations

[aeschli]

No description provided.

[Copilot]

Pull request overview

This PR updates the Copilot prompt assets so the /init skill is broader than “bootstrap workspace instructions”, and instead guides creation/updating of multiple chat customization artifacts (agent instructions, skills, custom agents).

Changes:

• Generalizes init skill copy to cover creating/updating multiple chat customization files (not just agent instructions).
• Renames “Workspace Instructions” terminology to “agent instructions” in the agent-customization skill tables and updates the reference link.
• Updates the agent-instructions reference doc title to match the new terminology.

Show a summary per file

File	Description
extensions/copilot/assets/prompts/skills/init/SKILL.md	Broadens /init guidance from “instructions” to multiple customization artifacts and adds guidance on how to proceed.
extensions/copilot/assets/prompts/skills/agent-customization/SKILL.md	Updates the customization primitive label + the quick reference link to the new agent-instructions reference.
extensions/copilot/assets/prompts/skills/agent-customization/references/agent-instructions.md	Updates the reference document title to the new term.

Copilot's findings

Comments suppressed due to low confidence (4)

extensions/copilot/assets/prompts/skills/init/SKILL.md:42

• More spelling issues in the guidelines list (“Prefern”, “can not”, “easely”). Since this file is used as a prompt/skill source, these typos can directly affect the generated customization content; please fix them.

   - New file: Prefern AGENTS.md over `.github/copilot-instructions.md`. If the user already has one of these files, update it instead of creating a new one. If both exist, update both.
   - Existing file: Preserve valuable content, update outdated sections, remove duplication
   - Follow the guidelines in **agent-customization.md**:
      1. **Link, don't embed** principle. Do not copy existing documentation that exists in the workspace, link to them with a Markdown link instead.
      2. **Minimal by default**: Only what's relevant and can not be easely discovered by an agent should be included. Link to other documentation for details.
      3. **Concise and actionable**: Every line should guide behavior

extensions/copilot/assets/prompts/skills/agent-customization/SKILL.md:18

• The primitive/type label “agent instructions” is lowercased, but other entries in these tables use title case (“File Instructions”, “Custom Agents”, etc.), and the product UI strings also use “Agent Instructions”. Consider capitalizing it consistently (“Agent Instructions”) in both tables.

This issue also appears on line 25 of the same file.

| Primitive | When to Use |
|-----------|-------------|
| agent instructions | Always-on, applies everywhere in the project |
| File Instructions | Explicit via `applyTo` patterns, or on-demand via `description` |
| MCP | Integrates external systems, APIs, or data |
| Hooks | Deterministic shell commands at agent lifecycle points (block tools, auto-format, inject context) |
| Custom Agents | Subagents for context isolation, or multi-stage workflows with tool restrictions |
| Prompts | Single focused task with parameterized inputs |

extensions/copilot/assets/prompts/skills/agent-customization/SKILL.md:28

• Same capitalization/terminology issue in the Quick Reference table: “agent instructions” stands out vs the other title-cased type names. For consistency with the rest of this document and other references, use “Agent Instructions”.

| Type | File | Location | Reference |
|------|------|----------|-----------|
| agent instructions | `copilot-instructions.md`, `AGENTS.md` | `.github/` or root | [Link](./references/agent-instructions.md) |
| File Instructions | `*.instructions.md` | `.github/instructions/` | [Link](./references/instructions.md) |

extensions/copilot/assets/prompts/skills/agent-customization/references/agent-instructions.md:1

• The main heading link text is lowercased (“agent instructions”), which is inconsistent with the other reference docs’ title casing and with the in-product label “Agent Instructions”. Consider updating the heading text to “Agent Instructions” for consistency and discoverability.

• Files reviewed: 3/3 changed files
• Comments generated: 3

[Copilot]

The instructions for new agent-instruction files conflict with the agent-instructions reference: this says to prefer AGENTS.md (even when copilot-instructions.md is marked as recommended in the reference) and to update both files if both exist, but the reference explicitly says to use only one file type (not both). Align /init guidance with the reference (choose one, and avoid encouraging both).

Suggested change

	- New file: Prefern AGENTS.md over `.github/copilot-instructions.md`. If the user already has one of these files, update it instead of creating a new one. If both exist, update both.
	- New file: Use `.github/copilot-instructions.md` as the agent instructions file. If that file already exists, update it instead of creating a new one. Do not create or maintain both `.github/copilot-instructions.md` and `AGENTS.md`.

[Copilot]

This references agent-customization.md, but there is no such file under extensions/copilot/assets/prompts/skills/ (the related asset is agent-customization/SKILL.md). Consider referencing the agent-customization skill by name or linking to the correct reference file so the instruction isn’t a dead link.

Suggested change

	- Follow the guidelines in **agent-customization.md**:
	- Follow the guidelines in the `agent-customization` skill:

[Copilot]

Spelling/grammar issues in this paragraph make the skill less clear and can leak into agent output (e.g., missing space after comma in “projects,the”, “immediatly”, “code base”, “Explord”, missing article in “give the user table”). Please correct these for clarity and consistency (VS Code generally uses “codebase”).

This issue also appears on line 37 of the same file.