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agent-customization

**WORKFLOW SKILL** — Create, update, review, fix, or debug VS Code agent customization files (.instructions.md, .prompt.md, .agent.md, SKILL.md, copilot-instructions.md, AGENTS.md). USE FOR: saving coding preferences; troubleshooting why instructions/skills/agents are ignored or not invoked; configuring applyTo patterns; defining tool restrictions; creating custom agent modes or specialized workflows; packaging domain knowledge; fixing YAML frontmatter syntax. DO NOT USE FOR: general coding questions (use default agent); runtime debugging or error diagnosis; MCP server configuration (use MCP docs directly); VS Code extension development. INVOKES: file system tools (read/write customization files), ask-questions tool (interview user for requirements), subagents for codebase exploration. FOR SINGLE OPERATIONS: For quick YAML frontmatter fixes or creating a single file from a known pattern, edit the file directly — no skill needed.

70

Quality

86%

Does it follow best practices?

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SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

78%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 instruction-only skill: clear decision tables, a sequenced creation workflow with validation, and clean progressive disclosure to verified reference files. The main gap is minor over-explanation in Common Pitfalls and the absence of an explicit error-retry feedback loop.

Suggestions

Tighten Common Pitfalls to the anti-pattern and the fix, dropping explanations of concepts Claude already knows (e.g. what applyTo:'**' means).

Add an explicit validate->fix->re-validate feedback loop to the Creation Process step 4 to push workflow clarity to 5.

Inline one minimal frontmatter template per primitive so single-file creation does not require loading a reference.

DimensionReasoningScore

Conciseness

Dense table-based structure is largely token-efficient, but the Common Pitfalls section includes some explanatory prose (e.g. 'applyTo: "**" burns context') that assumes knowledge Claude already has and could be trimmed.

4 / 5

Actionability

Concrete file-type/location tables and a named 4-step process give actionable guidance; minor gaps come from deferring frontmatter templates and examples to references rather than showing them inline.

4 / 5

Workflow Clarity

The Creation Process is a clear 4-step sequence with an explicit Validate checkpoint (location, frontmatter syntax, description present); it stops short of a validate->fix->retry feedback loop, leaving it just below a 5.

4 / 5

Progressive Disclosure

SKILL.md is a clean overview pointing via a table to six one-level-deep reference files, all of which exist, with detail appropriately split out — matching the score-5 anchor.

5 / 5

Total

17

/

20

Passed

Description

95%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, specific description with comprehensive trigger-term coverage and an explicit USE FOR / DO NOT USE structure. The only weakness is second-person phrasing in the boundary clauses, which triggers the rubric's voice penalty.

DimensionReasoningScore

Specificity

Lists many concrete actions ('Create, update, review, fix, or debug', 'configuring applyTo patterns', 'fixing YAML frontmatter syntax') with comprehensive coverage, matching the score-5 anchor; reduced by one per the second-person voice penalty ('use default agent', 'edit the file directly').

4 / 5

Completeness

Explicitly answers both what ('Create, update, review, fix, or debug VS Code agent customization files') and when (USE FOR / DO NOT USE FOR clauses with concrete triggers), matching the score-5 anchor.

5 / 5

Trigger Term Quality

Comprehensive coverage of natural terms and synonyms including concrete file extensions (.instructions.md, .prompts.md, .agent.md, SKILL.md, copilot-instructions.md, AGENTS.md) plus 'applyTo patterns' and 'YAML frontmatter'.

5 / 5

Distinctiveness Conflict Risk

Clear niche around VS Code agent customization files with distinct triggers, and the explicit DO NOT USE boundary minimizes overlap with general coding or MCP skills.

5 / 5

Total

19

/

20

Passed

Validation

93%

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

Validation15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

referenced_paths_exist

Referenced path issues: 1 missing

Warning

Total

15

/

16

Passed

Repository
posit-dev/positron
Reviewed

Table of Contents

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