npx skills add ...
npx skills add getsentry/warden --skill skill-writer
npx skills add getsentry/warden --skill skill-writer
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, depth gates, authoring, registration, and validation.
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.
Load only the path(s) required for the task. SKILL.md is the primary router: every bundled reference file should have a direct "open when..." reason here.
| 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 subfolders | 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 |
| run the full synthesis pass with depth gates 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 |
| troubleshoot overloaded layouts, hidden refs, or other structure failures | references/structure-troubleshooting.md |
| verify a risky, disputed, or explicitly requested change | references/evaluation-path.md |
| register the skill and run final validation checks | references/registration-validation.md |
| Open when you need to... | Read |
|---|---|
keep the whole skill inline in one coherent SKILL.md | references/artifact-layouts/inline-skill-layout.md |
| split optional deep knowledge into focused routed references | references/artifact-layouts/reference-backed-skill-layout.md |
| add scripts for deterministic automation or validation | references/artifact-layouts/script-backed-skill-layout.md |
| define a skill that is usually invoked with explicit arguments | references/artifact-layouts/argument-driven-skill-layout.md |
| ship reusable templates, schemas, or other static assets | references/artifact-layouts/asset-template-skill-layout.md |
| Open when you need to... | Read |
|---|---|
| break a task into fixed ordered steps | references/workflow-mechanics/prompt-chaining.md |
| classify requests and route them to different downstream paths | references/workflow-mechanics/routing-workflows.md |
| split independent work into parallel units or votes | references/workflow-mechanics/parallel-workflows.md |
| discover work units dynamically and coordinate worker outputs | references/workflow-mechanics/orchestrator-workers.md |
| critique and revise output against a rubric | references/workflow-mechanics/evaluator-loops.md |
| run validate-fix-repeat checks during authoring or execution | references/workflow-mechanics/validation-loops.md |
| validate a plan before executing a risky action | references/workflow-mechanics/plan-validate-execute.md |
| Open when you need to... | Read |
|---|---|
| use Claude-specific frontmatter or invocation controls | references/claude-code/frontmatter-and-invocation.md |
| use Claude argument fields or substitution variables | references/claude-code/argument-substitutions.md |
build a skill that runs in isolated context: fork | references/claude-code/subagent-fork-skills.md |
| build a skill that uses Claude hooks for deterministic enforcement | references/claude-code/hook-backed-skills.md |
| use Claude shell preprocessing for dynamic context injection | references/claude-code/dynamic-context.md |
| Open when you need to... | Read |
|---|---|
| see the expected depth for a documentation-heavy skill | references/examples/documentation-skill.md |
| see the expected depth for a security-review skill | references/examples/security-review-skill.md |
| see the expected depth for a workflow-process skill | references/examples/workflow-process-skill.md |
| see what a good routed skill looks like | references/examples/router-skill.md |
| see what a good evaluator-loop skill looks like | references/examples/evaluator-loop-skill.md |
| see what a good subagent-fork skill looks like | references/examples/subagent-fork-skill.md |
| see what a good hook-backed skill looks like | references/examples/hook-backed-skill.md |
create, update, synthesize, iterate) and inspect workspace prior art before choosing where files belong.references/mode-selection.md to choose the minimum required workflow paths.references/execution-shapes.md to choose the primary execution shape.Read references/synthesis-path.md.
references/source-discovery.md when source material is thin, stale, or ambiguous.Read references/iteration-path.md first when selected path includes iteration (for example operation iterate).
references/iteration-evidence.md when examples should persist beyond the current turn.Skip this step when selected path does not include iteration.
Read references/authoring-path.md.
SKILL.md in imperative voice with trigger-rich description.SKILL.md as the runtime router, not an encyclopedia.references/reference-architecture.md before adding bulk instructions or new reference files.SPEC.md using references/spec-template.md when creating a new skill or materially changing its contract.SKILL.md.Read references/description-optimization.md.
references/evaluation-path.md only when the user asks for evaluation, the change is high-risk, or the architecture choice is non-obvious.Read references/registration-validation.md.
Return:
SummaryChanges MadeValidation ResultsOpen Gaps