Use when designing, implementing, reviewing, testing, or cleaning up feature toggles, feature flags, kill switches, runtime configuration gates, canary controls, staged rollouts, experiments, or temporary compatibility switches in Java enterprise systems. This should trigger for requests such as Design a feature toggle strategy; Review this feature flag; Add a kill switch safely; Test toggle on and off paths; Clean up an expired feature toggle; Plan controlled rollout and rollback behavior. Part
SkillScore77Maintained
Automatic
◆Coding pack
Last verified 8/20/2026
What it changes
Passed 16 of 21 test cases with the skill, and 15 of 21 without it.
Without skill73%
With skill77%
Checks it passed that the model alone missed
The response requires testing toggle configuration failure behavior.
The output requires tracking decision volume and conversion metrics to evaluate the experiment.
The output includes explicit toggle metadata listing the classification type, owner, expected lifetime, default state, target audience, and removal trigger.
and 1 more in the full report
4 fixed13 passed either way2 still failing3 broke
Pass-rate lift
+5 pp
Tokens
+31%
Agent turns
0%
Response time
-1%
Model gemini-3.6-flashMeasured 8/20/2026v117 of 22 cases passed with skill · 21 comparable
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 4 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 4
Prompt
We have several conditional flags scattered across our Java service classes for a promotional discount feature that is now ending. Could you review this setup and provide a refactoring strategy? Deliver a complete report with a centralized design, tested rollback/fallback contracts, and a structured cleanup schedule with assigned ownership.
What was checked, without and with the skill
Checked
Without skill
With skill
The output includes explicit toggle metadata listing the classification type, owner, expected lifetime, default state, target audience, and removal trigger.
Missed
Passed
The output details a cleanup plan specifying removal steps for obsolete conditional branches and flag lookups.
Passed
Passed
case-03 · gemini-3.6-flash · 8/20/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md63 lines2 files
Feature Toggles Design
Guide Java Enterprise developers through safe feature toggle design and lifecycle management. This is an interactive SKILL.
What is covered in this Skill?
Deciding when a feature toggle is appropriate versus a branch, configuration change, deployment change, or parallel change
Implementing toggles in Java services without scattering flag checks or creating hidden long-term complexity
Reviewing toggles for release, rollback, security, privacy, concurrency, and maintenance risk
Testing both enabled and disabled paths, configuration failure behavior, rollout rules, and cleanup readiness
Constraints
Use feature toggles as explicit, owned runtime control points rather than hidden conditional complexity.
MUST read references/057-design-feature-toggles.md before applying feature toggle guidance
MUST classify the toggle type, owner, expected lifetime, default state, rollout audience, and removal trigger before recommending implementation
MUST design safe defaults, fallback behavior, observability, and rollback behavior for runtime evaluation failures
MUST keep toggle evaluation centralized, typed, and testable instead of scattering raw configuration lookups through business logic
MUST include cleanup expectations for temporary toggles before implementation is considered complete
MUST NOT use feature toggles to hide incomplete design decisions, weaken security controls, or leave permanent branches without explicit ownership
When to use this skill
Design a feature toggle strategy
Review this feature flag implementation
Add a kill switch safely
Plan a canary or staged rollout in a Java service
Test toggle on and off paths
Clean up an expired feature toggle
Decide whether this runtime behavior change needs a toggle
Workflow
Classify the Toggle Need
Read references/057-design-feature-toggles.md, then identify the runtime behavior change, rollout risk, rollback expectation, affected users, operational owner, and whether a feature toggle is the smallest safe control mechanism.
Use when you need to review, improve, or troubleshoot a Maven pom.xml file — including dependency management with BOMs, plugin configuration, version centralization, multi-module project structure, build profiles, or any situation where you want to align your Maven setup with industry best practices. This should trigger for requests such as Review pom.xml to improve it; Apply Maven best practices to pom.xml; Improve Maven POM configuration; Review Maven dependency management and plugin configura