copilot-prompting

Copilot Prompting

Use this skill when copilot:copilot-delegate needs to compose a prompt for the Copilot companion runtime.

Prompt Copilot like an operator, not a collaborator. Keep prompts compact and block-structured with clear sections. State the task, the output contract, the follow-through defaults, and the small set of extra constraints that matter.

Core rules:

• Prefer one clear task per Copilot run. Split unrelated asks into separate runs.
• Tell Copilot what done looks like. Do not assume it will infer the desired end state.
• Add explicit grounding and verification rules for any task where unsupported guesses would hurt quality.
• Prefer better prompt contracts over adding long natural-language explanations.
• Use explicit contracts over vague nudges.

Block-structured prompt format:

• Context: repository context, git branch, recent changes, relevant architecture notes.
• Task: the concrete job, scope, and what done looks like.
• Constraints: boundaries, what not to touch, required patterns, size limits.
• Output Format: exact shape, ordering, and brevity requirements. Request structured JSON output for machine-parseable results.

Model-specific guidance: Copilot supports multiple backend models including GPT-5, Claude, and Gemini. Tailor prompts to model strengths:

• GPT-5: strong at structured output, code generation, and following detailed XML/JSON contracts. Use explicit output schemas.
• Claude: strong at nuanced reasoning, long-context analysis, and careful instruction following. Provide clear task decomposition.
• Gemini: strong at search-grounded research, multimodal analysis, and broad knowledge tasks. Include search context when relevant.

When to add sections:

• Coding or debugging: add verification criteria and missing-context handling.
• Review or adversarial review: add grounding rules and structured output contract.
• Research or recommendation tasks: add citation requirements and search context.
• Write-capable tasks: add action safety constraints so Copilot stays narrow and avoids unrelated refactors.

Repository context inclusion:

• Include the current git branch name when relevant to the task.
• Include recent commit messages or diff summary when reviewing changes.
• Include relevant architecture notes or patterns from the codebase when the task depends on them.
• Do not include entire file contents unless the task specifically requires them.

Prompt assembly checklist:

1. Define the exact task and scope in the Context and Task sections.
2. Choose the smallest output contract that still makes the answer easy to use.
3. Decide whether Copilot should keep going by default or stop for missing high-risk details.
4. Add verification, grounding, and safety constraints only where the task needs them.
5. Remove redundant instructions before sending the prompt.