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make-custom-agent

Create, review, or fix custom GitHub Copilot agents. Use when asked to create, scaffold, configure, review, or restrict a custom agent, declarative agent, or @-invokable chat participant for GitHub Copilot.

68

Quality

85%

Does it follow best practices?

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SecuritybySnyk

Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

75%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured, actionable skill body: the declarative fast path is fully specified, steps are clearly sequenced, and validation exists as a checklist. Weaknesses are incremental — a missing error-recovery loop after validation, a couple of incomplete code snippets in the extension path, and advanced-path content inlined that could live in reference files.

Suggestions

Add a feedback loop to Step 8: after the validation checklist, instruct what to do on failure (e.g., 'If frontmatter YAML is invalid, fix the syntax and re-run the checklist before proceeding') so validation is a checkpoint, not a one-shot list.

Complete the tool-calling snippet in Step 5 by showing the import/source of `chatUtils` (e.g., the `@vscode/chat-extension-utils` import) so the code is copy-paste runnable.

Move the extension-based participant (Step 5) and GitHub App (Step 6) details into reference files (e.g., references/extension-based.md, references/github-app.md) and keep one-line pointers in SKILL.md, keeping the main file lean for the common declarative path.

DimensionReasoningScore

Conciseness

The body is efficient and domain-specific (frontmatter field table, tool patterns, pitfalls table) with only minor trim opportunities — e.g., the "Handoff fields" bullets restate what the YAML example already shows, and the declarative template's placeholder sections slightly pad. This fits the anchor 'efficient; minor instances of over-explanation that could be trimmed' rather than the every-token-earns-its-place level.

4 / 5

Actionability

Mostly executable guidance: file location `.github/agents/<name>.md`, a complete frontmatter table, copy-paste package.json and activate/handler TypeScript, and a concrete eval path (`eng/harness-evaluation/agents/<agent-id>/eval.yaml`). Minor gaps keep it below fully-executable: the tool-calling snippet uses `chatUtils.sendChatParticipantRequest` without showing its import, and Step 6 (GitHub App) has no code, only a documentation link.

4 / 5

Workflow Clarity

Eight clearly numbered steps (choose type → create → tools → handoffs → extension → GitHub App → eval → validate) with a validation checklist in Step 8, matching 'clear sequence with most checkpoints present'. Not a 5 because there is no error-recovery feedback loop (the checklist says what to verify but not what to do on failure, e.g., invalid frontmatter YAML → fix and re-check).

4 / 5

Progressive Disclosure

Good structure with clear sections, a References list of relevant external links, and no nested-reference problem (no bundle files exist; body references are one level deep). Minor gap: the two advanced paths — the ~70-line extension-based section (Step 5) and the GitHub App section — are inlined in SKILL.md when most users need only the declarative path, so splitting them into reference files would match the anchor's 'content appropriately split' ideal.

4 / 5

Total

16

/

20

Passed

Description

88%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: it pairs a concrete what-clause with an explicit 'Use when' clause rich in natural trigger terms and domain synonyms. The only gaps are a few missing synonyms for the extension/GitHub App path and mild ambiguity of the bare word 'agent' across ecosystems.

DimensionReasoningScore

Specificity

"Create, review, or fix custom GitHub Copilot agents" plus "create, scaffold, configure, review, or restrict" names six distinct concrete actions across the domain (declarative agent, @-invokable chat participant), matching the anchor for multiple specific concrete actions with comprehensive coverage; it exceeds the score-4 anchor ('several specific actions; minor gaps') because the verb set spans the skill's full lifecycle.

5 / 5

Completeness

The first sentence explicitly answers what ("Create, review, or fix custom GitHub Copilot agents") and the second gives an explicit when with concrete trigger phrases ("Use when asked to create, scaffold, configure, review, or restrict..."), which matches the score-5 anchor exactly; both clauses are present and specific, so the score-4 anchor's weaker 'when' does not apply.

5 / 5

Trigger Term Quality

Natural phrases users would say are well covered ("custom agent", "declarative agent", "@-invokable chat participant", "scaffold", "configure", "restrict"), matching the good-coverage anchor; not a 5 because a few natural terms are missing — e.g., "Copilot Extension" / "GitHub App" for the cross-surface path the body covers, and file-location cues like ".github/agents".

4 / 5

Distinctiveness Conflict Risk

The niche is clear ("custom GitHub Copilot agents", "@-invokable chat participant") and mostly distinct, but "custom agent" alone is overloaded across harnesses (e.g., non-Copilot subagents) and the body notes closely related skills (make-skill, make-instructions), so minor overlap risk with closely related skills remains — the score-5 anchor's 'minimal conflict risk' is not fully met.

4 / 5

Total

18

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

dotnet/efcore

Path

.agents/skills/make-custom-agent/SKILL.md

Reviewed

Table of Contents

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