Skill Writer

SentryOfficialPublished by Sentry

Skill
Meta (authoring, orchestration, planning, memory)
Agent tooling
Apache-2.0
Low risk
Has scripts

From the author

Create, synthesize, and iteratively improve agent skills following the Agent Skills specification. Use when asked to "create a skill", "write a skill", "synthesize sources into a skill", "improve a skill from positive/negative examples", "update a skill", or "maintain skill docs and registration". Handles source capture, precision passes, authoring, registration, and validation.

— the description by Sentry

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

Skill Writer provides a standardized, multi-step framework for the full lifecycle of agent skill development. It acts as a router and guide, ensuring that skills are built with high-value coverage, proper architectural layout, and clear maintenance contracts. By following its defined paths—ranging from synthesis and authoring to iteration and validation—users can produce robust, portable, and well-documented skills that adhere to established design principles and precision standards.

What it does

Guides the creation and synthesis of new agent skills from raw sources.
Facilitates iterative improvements based on positive and negative performance examples.
Enforces a structured reference architecture for skill documentation and runtime files.
Provides precision passes to ensure changes are necessary, concise, and impactful.
Supports the registration and validation of skills to ensure structural integrity.
Offers specialized paths for different execution shapes like routers, subagents, and scripts.

When to use it

When you need to create a new agent skill from scratch.
When updating or improving an existing skill's logic or documentation.
When synthesizing disparate sources into a cohesive, functional skill.
When you need to refine a skill's behavior based on specific success or failure examples.
When maintaining skill documentation and ensuring it meets registration standards.

Advantages

Ensures consistency across all developed agent skills.
Minimizes wasted runtime tokens by prioritizing high-value input coverage.
Provides clear, actionable paths for different levels of skill complexity.
Promotes modularity through a well-defined reference architecture.
Includes built-in precision checks to prevent unnecessary bloat or rule redundancy.

Usage examples

“Create a skill for managing cloud infrastructure deployments.”: The agent initiates the synthesis path, identifies the required execution shape, and guides you through authoring the SKILL.md and SPEC.md files.
“Improve this skill based on these failed test cases.”: The agent enters the iteration path, analyzes the provided evidence, and proposes specific updates to the skill's logic or documentation to resolve the failures.

Install

Download the skill as a ZIP:
https://mp-staging.autogineer.com/agent-skills/getsentry/skill-writer/download

Unzip it into the cross-client skills folder of your project:

mkdir -p .agents/skills && unzip skill-writer.zip -d .agents/skills

Documentation by Sentry

Skill Writer

Use this as the single canonical workflow for skill creation and improvement. Primary success condition: maximize high-value input coverage before authoring while minimizing wasted runtime tokens.

Follow the workflow steps in order. Load only the reference files required for the step you are on. SKILL.md is the primary router: every bundled reference file should be flat under references/ and listed here with a direct "open when..." reason.

Core Workflow References

Open when you need to...	Read
choose the minimum workflow path for create, update, iterate, or research-first work	`references/mode-selection.md`
choose the simplest adequate execution shape before deciding files	`references/execution-shapes.md`
apply writing constraints for depth, concision, and portability	`references/design-principles.md`
decide what belongs in `SKILL.md`, `references/`, `SPEC.md`, or supporting files	`references/reference-architecture.md`
create or update the maintenance contract for a skill	`references/spec-template.md`
find missing high-signal sources, including history and regressions	`references/source-discovery.md`
adapt an upstream prompt, workflow, rubric, benchmark, or docs into a skill	`references/source-adaptation.md`
run the full synthesis pass with coverage checks and source capture	`references/synthesis-path.md`
author or update `SKILL.md`, `SPEC.md`, and supporting files	`references/authoring-path.md`
improve trigger language and false-positive/false-negative behavior	`references/description-optimization.md`
iterate from positive, negative, or fix examples	`references/iteration-path.md`
store persistent working and holdout examples for future revisions	`references/iteration-evidence.md`
choose a response template, schema, or output contract	`references/output-contracts.md`
add or update evals for a skill's generated outputs or runtime behavior	`references/skill-evals.md`
troubleshoot overloaded layouts, hidden refs, or other structure failures	`references/structure-troubleshooting.md`
register the skill and run final validation checks	`references/registration-validation.md`

Artifact Layout References

Open when you need to...	Read
keep the whole skill inline in one coherent `SKILL.md`	`references/layout-inline-skill.md`
split optional deep knowledge into focused routed references	`references/layout-reference-backed-skill.md`
add scripts for deterministic automation or validation	`references/layout-script-backed-workflow.md`
define a skill that is usually invoked with explicit arguments	`references/layout-argument-driven-skill.md`
ship reusable templates, schemas, or other static assets	`references/layout-asset-template-skill.md`

Workflow Mechanic References

Open when you need to...	Read
break a task into fixed ordered steps	`references/workflow-prompt-chaining.md`
classify requests and route them to different downstream paths	`references/workflow-routing.md`
split independent work into parallel units or votes	`references/workflow-parallel.md`
discover work units dynamically and coordinate worker outputs	`references/workflow-orchestrator-workers.md`
run validate-fix-repeat checks during authoring or execution	`references/workflow-validation-loops.md`
validate a plan before executing a risky action	`references/workflow-plan-validate-execute.md`

Claude Code References

Open when you need to...	Read
use Claude-specific frontmatter or invocation controls	`references/claude-frontmatter-invocation.md`
use Claude argument fields or substitution variables	`references/claude-argument-substitutions.md`
build a skill that runs in isolated `context: fork`	`references/claude-subagent-fork.md`
build a skill that uses Claude hooks for deterministic enforcement	`references/claude-hook-backed.md`
use Claude shell preprocessing for dynamic context injection	`references/claude-dynamic-context.md`

Example Profiles

Open when you need to...	Read
see the expected depth for a documentation-heavy skill	`references/example-documentation-skill.md`
see the expected depth for a workflow-process skill	`references/example-workflow-process-skill.md`
see what a good routed skill looks like	`references/example-router-skill.md`
see what a good subagent-fork skill looks like	`references/example-subagent-fork-skill.md`
see what a good hook-backed skill looks like	`references/example-hook-backed-skill.md`

Step 1: Resolve target, path, and shape

Resolve the intended operation (create, update, synthesize, iterate) and inspect workspace prior art before choosing where files belong.
Choose the target skill root from observed conventions. If the canonical location is still unclear after inspection, ask one direct question before editing files.
Read references/mode-selection.md to choose the minimum required workflow paths.
Read references/execution-shapes.md to choose the primary execution shape.
Default to the simplest adequate shape. If selecting a more complex shape, record why simpler shapes were rejected.
Load only the exact artifact-layout, workflow-mechanic, and provider-specific leaf files required by that shape.
Before adding guidance, identify what existing rule, section, or file should be narrowed, replaced, or removed.
Record portability implications before using provider-specific mechanics.

Step 2: Run synthesis when needed

Read references/synthesis-path.md.

Use this path for new skills, material changes, and research-first planning.
Collect and score relevant sources with provenance.
Read references/source-discovery.md when source material is thin, stale, or ambiguous.
Read references/source-adaptation.md when adapting an upstream prompt, workflow, rubric, benchmark, or docs.
Produce source-backed decisions and coverage/gap status, including the class and execution-shape choice.
Load example profiles only when they add concrete depth for the selected class or shape.
If the skill uses provider-specific mechanics, include current official provider docs and capture usage constraints.
Do not move to authoring until required coverage is understood or gaps are explicit.

Step 3: Run iteration first when improving from outcomes/examples

Read references/iteration-path.md first when selected path includes iteration (for example operation iterate).

Capture and anonymize examples with provenance.
Read references/iteration-evidence.md when examples should persist beyond the current turn.
Review skill behavior against working and holdout slices.
Propose improvements from positive/negative/fix evidence.
Carry concrete behavior deltas into authoring.

Skip this step when selected path does not include iteration.

Step 4: Author or update skill artifacts

Read references/authoring-path.md.

Write or update SKILL.md in imperative voice with trigger-rich description.
Keep SKILL.md as the runtime router, not an encyclopedia.
Run the pre-edit precision check in references/authoring-path.md before creating new sections or files.
Read references/reference-architecture.md before adding bulk instructions or new reference files.
Create or update SPEC.md using references/spec-template.md when creating a new skill or materially changing its contract.
Create focused reference files, scripts, and assets only when each one has a clear "open when..." reason and cannot be handled by tightening an existing file.
If you add a bundled reference file, add a direct routing entry for it in this SKILL.md.
Prefer checklists, tables, templates, and input/output examples over explanatory prose.
Follow only the specific artifact-layout, workflow-mechanic, Claude-specific, and output-contract references selected for this skill.
For advanced execution shapes, add the required routing, delegation, or safety contracts before considering the skill complete.
For authoring/generator skills, include transformed examples in references:

happy-path
secure/robust variant
anti-pattern + corrected version

Read references/skill-evals.md when the request asks for evals, regression cases, benchmark cases, or model-graded quality checks for the skill being authored.
After any skill artifact changes, run the post-change precision pass in references/authoring-path.md before description optimization or validation.

Step 5: Optimize description quality

Read references/description-optimization.md.

Validate should-trigger and should-not-trigger query sets.
Reduce false positives and false negatives with targeted description edits.
Keep trigger language generic across providers unless the skill is intentionally provider-specific.

Step 6: Register and validate

Read references/registration-validation.md.

Apply repository registration steps for the active layout you verified in the workspace.
Run quick validation for structural checks.
Review validator warnings, precision-pass results, and coverage gaps with judgment before completion.

Output format

Return:

Summary
Changes Made
Validation Results
Open Gaps

Files

ATTRIBUTION.mdAdded by AutoGineer848 B
EVAL.md6.4 KiB
LICENSELicence file added by AutoGineer10.5 KiB
SKILL.md9.8 KiB
SOURCES.md19.1 KiB
SPEC.md9.7 KiB
evals/axis.config.json318 B
evals/scenarios/iteration-from-bad-output.json2.8 KiB
evals/scenarios/reference-backed-integration.json1.9 KiB
evals/scenarios/small-inline-workflow.json1.9 KiB
references/authoring-path.md4.7 KiB
references/claude-argument-substitutions.md624 B
references/claude-dynamic-context.md579 B
references/claude-frontmatter-invocation.md1.9 KiB
references/claude-hook-backed.md913 B
references/claude-subagent-fork.md718 B
references/description-optimization.md1.0 KiB
references/design-principles.md3.6 KiB
references/example-documentation-skill.md2.8 KiB
references/example-hook-backed-skill.md989 B
references/example-router-skill.md1.0 KiB
references/example-subagent-fork-skill.md1.1 KiB
references/example-workflow-process-skill.md2.4 KiB
references/execution-shapes.md4.6 KiB
references/iteration-evidence.md2.6 KiB
references/iteration-path.md1.5 KiB
references/layout-argument-driven-skill.md1.0 KiB
references/layout-asset-template-skill.md809 B
references/layout-inline-skill.md731 B
references/layout-reference-backed-skill.md1.2 KiB
references/layout-script-backed-workflow.md846 B
references/mode-selection.md3.2 KiB
references/output-contracts.md1.1 KiB
references/reference-architecture.md2.5 KiB
references/registration-validation.md3.5 KiB
references/skill-evals.md5.6 KiB
references/source-adaptation.md2.1 KiB
references/source-discovery.md2.6 KiB
references/spec-template.md2.2 KiB
references/structure-troubleshooting.md4.0 KiB
references/synthesis-path.md3.7 KiB
references/workflow-orchestrator-workers.md652 B
references/workflow-parallel.md540 B
references/workflow-plan-validate-execute.md678 B
references/workflow-prompt-chaining.md548 B
references/workflow-routing.md828 B
references/workflow-validation-loops.md658 B
scripts/quick_validate.pyScript4.6 KiB

SOURCES.md

Sources

This file tracks source material synthesized into skill-writer, plus iterative changes over time.

Current source inventory

Source	Type	Trust tier	Retrieved	Confidence	Contribution	Usage constraints	Notes
`SKILL.md`	local canonical	canonical	2026-05-01	high	Baseline orchestration, path model, and runtime contract	local active skill root	Primary source of current behavior
`references/*.md`	local canonical	canonical	2026-05-05	high	Detailed path guidance, examples, routed leaf references, and validation requirements	local active skill root	Flat runtime reference files listed directly from `SKILL.md`
`SPEC.md`	local canonical	canonical	2026-05-05	high	Canonical maintenance contract for intent, scope, evidence model, validation, and limitations	local active skill root	Updated to treat `skill-writer` as a meta-router
`https://agentskills.io/specification`	external canonical spec	canonical	2026-05-01	high	Portable skill structure, frontmatter, progressive disclosure, optional directories, and file-reference rules	spec-level constraints take precedence over local preferences	Cross-agent compatibility baseline
`https://agentskills.io/skill-creation/evaluating-skills`	external official docs	canonical	2026-06-30	high	Evaluation guidance: run isolated task cases, compare outputs to a baseline, and judge invocation plus output quality	skill-authoring evaluation guidance, not a deterministic validator spec	Informed `EVAL.md`
`https://platform.openai.com/docs/guides/evals`	external official docs	canonical	2026-06-30	high	Behavior-driven eval structure, test inputs, testing criteria, result analysis, and iteration loop	Evals platform is deprecated; retain general evaluation principles only	Informed `EVAL.md`
`https://platform.openai.com/docs/guides/graders`	external official docs	canonical	2026-06-30	high	Deterministic graders, model graders, evidence-bearing grading, smooth scores, and reward-hacking cautions	Graders product path is deprecated; retain judge design principles only	Informed LLM judge guidance
`https://github.com/anthropics/skills/tree/main/skills/skill-creator`	external official/adjacent skill	secondary	2026-06-30	high	Skill-eval loop with baseline runs, assertions after first outputs, timing capture, benchmark aggregation, human review, and blind comparison	Adapt concepts to this repo's Codex workflow rather than copying Claude-specific mechanics	Informed `EVAL.md` and eval case criteria
`https://axis.run/`	external eval tooling	secondary	2026-06-30	high	Open source coding-agent eval harness with scenarios, built-in Codex support, isolated workspaces, judge checks, reports, artifacts, and baselines	use for skill evals that must run real coding agents through Codex; avoid custom runners unless AXIS cannot express the case	Informed prescriptive eval framework
`https://www.promptfoo.dev/docs/providers/openrouter/`	external eval tooling	secondary	2026-06-30	medium	First-class OpenRouter provider syntax and API key/base URL configuration	rejected for skill evals because it does not exercise the Codex harness without custom glue	Preserved as research provenance only
Codex manual: noninteractive mode, SDK, and Record & Replay	external official docs	canonical	2026-06-30	high	`codex exec --json`, `--output-schema`, sandbox, final-message output, SDK orchestration option, and skill recording guidance	Codex harness requirements are satisfied through AXIS's Codex adapter for repeatable skill evals	Informed AXIS requirement checks
local `codex exec --help`	local tooling	canonical	2026-06-30	high	Installed CLI flag availability for ephemeral runs, output schemas, and working directory selection	local CLI behavior may vary by installed Codex version	Cross-checked manual guidance
`https://agentskills.io/skill-creation/best-practices`	external official docs	canonical	2026-05-01	high	Coherent unit design, moderate detail, progressive disclosure, defaults over menus, validation loops, plan-validate-execute	skill-authoring guidance, not provider-specific runtime semantics	Informed shape-selection and workflow guidance
`https://agentskills.io/skill-creation/using-scripts`	external official docs	canonical	2026-05-01	high	Script bundling, non-interactive requirements, `--help`, structured output, and safe script interfaces	script examples are illustrative, adapt to local tooling	Informed script-backed workflow requirements
`https://code.claude.com/docs/en/skills`	external official docs	canonical	2026-05-01	high	Current Claude Code skill lifecycle, frontmatter fields, argument features, `context: fork`, `allowed-tools`, and hooks-in-skills support	provider-specific; do not generalize to portable Agent Skills behavior	Replaced stale local assumptions about Claude-specific fields
`https://code.claude.com/docs/en/sub-agents`	external official docs	canonical	2026-05-01	high	Automatic delegation, focused subagents, explicit invocation modes, and subagent lifecycle integration	provider-specific	Informed `subagent-fork` shape guidance
`https://code.claude.com/docs/en/hooks`	external official docs	canonical	2026-05-01	high	Hook lifecycle, hooks in skills and agents, async constraints, and security requirements	provider-specific and security-sensitive	Informed `hook-backed` shape guidance and safety notes
`https://www.anthropic.com/engineering/building-effective-agents`	external official engineering guidance	canonical	2026-05-01	high	Simplicity-first design and workflow taxonomy such as prompt chaining, routing, parallelization, and orchestrator-workers	conceptual guidance; adapt to skill authoring rather than full app orchestration	Core source for execution-shape taxonomy
`https://developers.openai.com/api/docs/guides/reasoning-best-practices`	external official docs	canonical	2026-05-01	high	Planner/doer distinction, reasoning-vs-GPT model tradeoffs, and avoiding explicit chain-of-thought prompting	provider-specific model guidance; use only as general orchestration input unless exact product syntax matters	Informed reasoning-model notes
`https://openai.com/business/guides-and-resources/a-practical-guide-to-building-ai-agents/`	external official guidance	canonical	2026-05-01	high	Maximize a single agent first, use multi-agent only when needed, manager-vs-handoff split, layered guardrails	product-level guidance, not a skills standard	Informed simplicity rule and advanced-shape escalation criteria
`https://openai.github.io/openai-agents-python/agents/`	external official SDK docs	canonical	2026-05-01	medium	Manager-vs-handoff distinction and structured-output support	SDK-specific implementation details	Informed router/orchestrator language and contract expectations
`https://openai.github.io/openai-agents-python/handoffs/`	external official SDK docs	canonical	2026-05-01	medium	Handoff metadata, input filters, and receiving-agent history control	SDK-specific implementation details	Informed route/handoff contract guidance
`https://huggingface.co/docs/hub/model-cards`	external documentation pattern	secondary	2026-04-26	high	Model-card sections for intended use, data, limitations, and reproducibility	adapted as documentation prior art, not a skill standard	Inspired `SPEC.md` maintenance contract shape
`https://huggingface.co/docs/hub/en/model-card-annotated`	external documentation pattern	secondary	2026-04-26	high	Annotated intended-use, out-of-scope, risks, and limitations sections	adapted as documentation prior art, not a skill standard	Informed SPEC scope and limitations sections
`https://cacm.acm.org/research/datasheets-for-datasets/`	research/documentation pattern	secondary	2026-04-26	high	Data provenance, collection, composition, intended use, and maintenance transparency	adapted from dataset documentation to skill evidence documentation	Informed source/evidence model and privacy rules
`https://diataxis.fr/`	documentation framework	secondary	2026-04-26	high	User-need-centered documentation types: tutorial, how-to, reference, explanation	adapted as information architecture prior art, not a skill standard	Informed reference files as lookup needs rather than topic buckets
`https://dita-lang.org/`	documentation standard	secondary	2026-04-26	high	Topic-oriented technical content patterns: task, concept, reference, troubleshooting	adapted as documentation architecture prior art	Informed reference type table and troubleshooting matrix guidance
`https://www.writethedocs.org/guide/writing/docs-principles/`	documentation guidance	secondary	2026-04-26	medium	Documentation should be structured for findability, reuse, and user participation	general writing guidance	Cross-check for reference architecture usability
`AGENTS.md`	repo convention	canonical	2026-05-01	high	Repository-specific workflow requirements and registration checklist	repository-local policy	Registration + validator expectations
`README.md`	repo convention	canonical	2026-05-01	high	Skill table format and authoring conventions	repository-local policy	Registration and discoverability source

Decisions

skill-writer is a meta-router: it must choose both a skill class and an execution shape before authoring.
Default to the simplest adequate shape. Advanced mechanics require evidence and an explicit reason simpler shapes were rejected.
Skill class and execution shape are independent axes. Class drives coverage requirements; shape drives runtime mechanics and artifact layout.
SKILL.md remains the orchestration/index layer; references, scripts, assets, hooks, and subagents are leaves selected by that router.
Provider-specific Claude Code features are valuable but not default. Use them only when justified and record portability implications.
Claude-specific frontmatter guidance should track the current code.claude.com/docs/en/skills fields, including when_to_use, arguments, effort, paths, shell, context, agent, and hooks.
Router, parallel/orchestrator, subagent-fork, and hook-backed shapes each require explicit contracts, not just prose.
Hooks are deterministic enforcement and need narrow scope plus security notes because command hooks run with full user permissions.
Multi-agent guidance should distinguish manager/orchestrator, handoff, and isolated subagent execution instead of collapsing them into one pattern.
Reasoning-model guidance is a design option, not a universal default: planner/doer splits are useful when complexity warrants them.
Architectural choices are reviewed qualitatively during authoring, not inferred by validator heuristics.
Reference files remain split by lookup need rather than topic buckets, even as the set of supported shapes expands.
Runtime references stay flat under references/; related leaves use filename prefixes, and every bundled reference is directly discoverable from SKILL.md.
The validator should enforce durable structural guarantees and required fields, but should not hardcode name style, path-portability scans, skill classes, source-coverage schemas, SPEC headings, trigger-quality heuristics, or provider-specific optional frontmatter keys.
skill-writer should default to dense structures such as tables, checklists, templates, and I/O examples, and should cut explanatory prose unless it prevents a concrete mistake.
SKILL.md should stay a thin router; repeated policy belongs in routed references rather than always-loaded step prose.
Validation stays lightweight and structural; qualitative precision remains an authoring judgment.
Missing referenced bundled files are structural failures because they break runtime loading.
Generated skill quality should be evaluated with repo-level repeatable task cases, baseline comparison, and a rubric rather than by adding semantic heuristics to quick_validate.py.
Eval cases for skill-writer itself belong outside runtime SKILL.md routing so they do not affect normal skill use.
The prescriptive default for skill evals is AXIS with agents: ["codex"] when the eval must exercise Codex; AXIS uses the Codex codex exec --json harness while adding scenarios, artifacts, reports, judge checks, and baselines.
Promptfoo is not part of the prescribed skill-eval path; AXIS is the only framework choice for skill evals in this repo.
skill-writer needs runtime guidance for authoring evals for other skills, but its own maintainer eval files must stay out of SKILL.md routing.
Skill evals should combine deterministic assertions with LLM-as-judge for qualitative dimensions and require concrete evidence for every grade.

Coverage matrix

Dimension	Coverage status	Evidence
SKILL.md vs references placement	complete	Agent Skills spec, local reference architecture
Reference splitting heuristics	complete	Agent Skills best practices, Diataxis, DITA, local reference architecture and artifact-layout guidance
Long reference navigation	complete	local design principles
Source discovery beyond docs	complete	local synthesis coverage checks, repository history practices
Commit log as source material	complete	local source-discovery guidance
Positive/negative evidence storage	complete	local iteration path, prior validation guidance
Skill maintenance specification	complete	model cards, datasheets, local `SPEC.md` reference implementation
Shape-selection framework	complete	Anthropic effective agents, OpenAI practical guide, local execution-shapes guidance
Router/orchestrator patterns	complete	Anthropic effective agents, OpenAI agent guides, local workflow-mechanics guidance
Current Claude skill frontmatter and lifecycle mechanics	complete	Claude Code skills docs
Subagent-fork guidance	complete	Claude Code skills docs, subagents docs
Hook-backed guidance and security constraints	complete	Claude Code hooks docs
Script-backed workflow design	complete	Agent Skills using scripts guide
Skill-output evaluation	complete	Agent Skills evaluating skills guide, local iteration evidence model
Planner/doer reasoning guidance	complete	OpenAI reasoning best practices
Lookup-oriented reference architecture	complete	Diataxis user needs, DITA topic types, local reference architecture
Flat reference routing	complete	local reference architecture, user feedback on generator simplicity

Open gaps

Advanced-shape contracts still rely on author judgment and review rather than deterministic validation.
This repository still has few real shipped examples using hooks, context: fork, when_to_use, arguments, paths, or effort.
Public repo docs outside skill-writer may need follow-up updates to fully reflect the current Claude-specific skill fields.
The initial skill-writer eval cases are synthetic; they should be replaced or expanded with real generated-output regressions over time.
AXIS is now the eval harness, but the initial scenarios are still synthetic and should be calibrated against real generated-output regressions.

Changelog

2026-03-05: Initialized SOURCES.md with baseline source pack (local canonical, Codex upstream, Claude upstream, spec, and repo conventions).
2026-03-19: Clarified path-resolution guidance so bundled skill references stay skill-root-relative while registration steps are resolved from the repository's active layout.
2026-03-19: Made portability a default authoring rule and emphasized avoiding host-specific absolute filesystem paths.
2026-04-19: Updated path guidance to preserve repository-standard root variables such as ${CLAUDE_SKILL_ROOT} instead of banning them outright.
2026-05-09: Replaced ${CLAUDE_SKILL_ROOT} guidance with skill-root-relative paths. Environment variable path prefixes cause permission friction and runtime failures in Claude Code.
2026-04-19: Restored .agents/skills as the default authoring target and kept repository-specific layouts as an inspected override rather than the default.
2026-04-19: Added explicit prior-art inspection and user-confirmation guidance when the correct skill root is unclear.
2026-04-26: Added reference architecture, source discovery, and iteration evidence guidance; updated synthesis, authoring, and iteration paths to prevent overloaded SKILL.md and catch-all reference files.
2026-04-26: Added SPEC.md as the canonical skill-writer maintenance specification and added references/spec-template.md for future skills.
2026-04-26: Removed fixed integration reference filename validation and added length-based reference warnings.
2026-04-26: Reworked reference architecture around concrete lookup needs instead of generic topic buckets.
2026-05-01: Reworked skill-writer around explicit execution-shape routing, added shape-specific example profiles, refreshed Claude Code provider mechanics from current official docs, and added source guidance for routing, delegation, and hooks.
2026-05-01: Replaced generic pattern bucket references with routed leaf files and made SKILL.md enumerate every bundled reference file with a direct open-when reason.
2026-05-01: Removed the validator's hardcoded optional frontmatter allowlist so provider-specific field drift does not create noisy false warnings.
2026-05-01: Reduced prose-heavy guidance in skill-writer, rewrote the main runtime refs into denser tables/checklists, and made compact runtime guidance an explicit contract.
2026-05-01: Thinned SKILL.md back toward a true router and removed duplicated execution-shape detail from mode-selection.md.
2026-05-05: Flattened runtime reference files under references/, kept SKILL.md as the complete material index, removed unused runbooks, added source-adaptation guidance, and made precision passes part of every skill create/update flow while keeping validation lightweight.
2026-05-05: Removed validator skill-class inference, integration coverage parsing, SPEC heading checks, SOURCES schema checks, and description-style heuristics.
2026-05-05: Removed validator name-style checks and machine-specific path scanning; kept only format, required fields, directory-name match, referenced-file existence, and a high-threshold size warning.
2026-06-30: Added skills/skill-writer/EVAL.md, evals/axis.config.json, and AXIS scenarios with baseline comparison guidance, working/holdout cases, artifact capture, judge checks, and semantic grading that stays out of the structural validator and runtime SKILL.md.
2026-06-30: Replaced framework-first and custom-runner eval guidance with AXIS as the prescriptive open source skill-eval harness. AXIS satisfies the Codex-harness requirement through its built-in codex adapter while adding reports, artifacts, transcripts, and baselines.
2026-06-30: Added references/skill-evals.md so skill-writer can author skill-specific eval playbooks and cases without routing its own maintainer evals.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Needs: Needs Python

Security

What our scanner noticed· Low risk

Scripts that your agent may run

This skill includes scripts that your agent may run. Read them before you use it.

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Published by

Sentry

Publisher

Sentry (Official)

Source

getsentry/skills · skills/skill-writer · commit e94f222

Licence

Apache License 2.0 (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-08

AutoGineer is not affiliated with or endorsed by Sentry.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download skill-writer.zip

From the author

AutoGineer summary

What it does

When to use it

Advantages

Usage examples

Install

Documentation by Sentry

Skill Writer

Core Workflow References

Artifact Layout References

Workflow Mechanic References

Claude Code References

Example Profiles

Step 1: Resolve target, path, and shape

Step 2: Run synthesis when needed

Step 3: Run iteration first when improving from outcomes/examples

Step 4: Author or update skill artifacts

Step 5: Optimize description quality

Step 6: Register and validate

Output format

Files

SOURCES.md

Sources

Current source inventory

Decisions

Coverage matrix

Open gaps

Changelog

Requirements and compatibility

Security

Attribution and licence

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