chore(copilot): test prompt blocks from a review skill

[kirangadhave]

This pull request was authored by a coding agent.

📝 Summary

This PR tests whether GitHub Copilot code review honors agent-skill instructions that append copy-pasteable prompt blocks to line comments and the pull request overview.

The previous instruction-only experiment in #10559 did not produce the blocks. The follow-up in #10562 included the same templates in both .github/copilot-instructions.md and a review-focused skill, and the blocks appeared. This version keeps only .github/skills/code-review/SKILL.md, making the skill the single instruction source and avoiding duplicated templates that could drift.

GitHub documents both review-comment formatting changes and Pull Request Overview changes as unsupported instructions. This PR is an experiment to find out whether Copilot honors them at all; the behavior is not expected to be guaranteed.

For this PR, please include three dummy review comments so we can verify whether the prompt block appears on every line comment and in the overview.

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Project	Deployment	Actions	Updated (UTC)
marimo-docs	Ready	Preview	Aug 15, 2026 12:05am

[github-actions]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[Copilot]

Pull request overview

Adds a dedicated Copilot code-review skill that instructs the reviewer to append copy‑pasteable “Prompt for AI agents” blocks to line comments and the PR overview, consolidating the experiment’s templates into a single source of truth under .github/skills/.

Changes:

• Introduces .github/skills/code-review/SKILL.md with a standardized line-comment prompt block template.
• Adds a standardized PR-overview prompt block template that groups violations by file and severity.

---

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[cubic-dev-ai]

2 issues found across 1 file

Prompt for AI agents (unresolved issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name=".github/skills/code-review/SKILL.md">

<violation number="1" location=".github/skills/code-review/SKILL.md:11">
P3: The guidance is self-contradictory: it says to reproduce "the fence exactly as shown" but then says "Do not include the `~~~` lines," even though the only fence shown that wraps the block is the outer `~~~` fence. An executing model could interpret this as reproducing the `~~~` wrapper. Clarify that the copy-pasteable block is the inner `````text fence and that the outer `~~~` wrapper is only scaffolding. Apply the same fix in the "Overview comment format" section.</violation>

<violation number="2" location=".github/skills/code-review/SKILL.md:22">
P2: `<file context>` contains a space, which is not a valid XML/HTML tag name. Since this block is meant to be machine-consumable, use a valid tag name such as `file_context` or `file-context`.</violation>
</file>

Architecture diagram

sequenceDiagram
    participant Dev as Developer
    participant Copilot as GitHub Copilot
    participant Skill as Code Review Skill
    participant Inst as Instruction Parser
    participant Review as Review Generator
    participant PR as Pull Request

    Note over Dev,PR: Config Management Flow
    
    Dev->>Skill: Maintain SKILL.md
    Skill->>Inst: Load skill instructions

    Note over Copilot,PR: Review Execution Flow
    
    Copilot->>Skill: Request code review on PR
    Skill->>Inst: Parse skill format directives
    Inst-->>Skill: Return formatting rules
    Skill->>Review: Generate standard line comments
    Review->>Review: Format comments with prompt blocks
    Review->>Review: Append details block to each comment
    Review-->>PR: Post line comments with prompts
    
    Skill->>Review: Generate overview summary
    Review->>Review: Aggregate issues by file
    Review->>Review: Add details block to overview
    Review-->>PR: Post overview with prompt block
    
    Note over PR,Dev: Output Verification
    
    PR-->>Dev: Display comments and overview
    
    alt All format blocks present
        Dev->>Dev: Verify prompt blocks in comments
        Dev->>Dev: Confirm overview includes blocks
    else Some blocks missing
        Dev->>Dev: Note unsupported instruction behavior
    end

Loading

<sub>Reply with feedback, questions, or to request a fix.

Re-trigger cubic</sub>

[cubic-dev-ai]

P2: <file context> contains a space, which is not a valid XML/HTML tag name. Since this block is meant to be machine-consumable, use a valid tag name such as file_context or file-context.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At .github/skills/code-review/SKILL.md, line 22:

<comment>`<file context>` contains a space, which is not a valid XML/HTML tag name. Since this block is meant to be machine-consumable, use a valid tag name such as `file_context` or `file-context`.</comment>

<file context>
@@ -0,0 +1,56 @@
+
+<comment severity="<low|medium|high>"><THE TEXT OF YOUR REVIEW COMMENT></comment>
+
+<file context>
+<THE DIFF HUNK YOU COMMENTED ON>
+</file context>
</file context>

[cubic-dev-ai]

P3: The guidance is self-contradictory: it says to reproduce "the fence exactly as shown" but then says "Do not include the ~~~ lines," even though the only fence shown that wraps the block is the outer ~~~ fence. An executing model could interpret this as reproducing the ~~~ wrapper. Clarify that the copy-pasteable block is the inner `````text fence and that the outer ~~~ wrapper is only scaffolding. Apply the same fix in the "Overview comment format" section.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At .github/skills/code-review/SKILL.md, line 11:

<comment>The guidance is self-contradictory: it says to reproduce "the fence exactly as shown" but then says "Do not include the `~~~` lines," even though the only fence shown that wraps the block is the outer `~~~` fence. An executing model could interpret this as reproducing the `~~~` wrapper. Clarify that the copy-pasteable block is the inner `````text fence and that the outer `~~~` wrapper is only scaffolding. Apply the same fix in the "Overview comment format" section.</comment>

<file context>
@@ -0,0 +1,56 @@
+
+End every review comment you leave on a line of code with the block below.
+Fill each placeholder. Reproduce the wording, the `<details>` element, and the
+fence exactly as shown. Do not include the `~~~` lines.
+
+~~~
</file context>