| name | harms-check |
| description | Use when building anything USER-FACING (or with persuasion/retention/cancellation/consent/pricing flows, or that touches vulnerable people) to surface design-level harm the security/privacy/compliance gates miss: dark/deceptive patterns and foreseeable misuse. Assumes the product works as designed and asks who it could harm and whether it is Happier-negative. NUDGE, not a block. |
| metadata | {"instruction_budget":"44","framework_dependency":"mycelium","framework_dependency_note":"This skill is designed to run within the Mycelium framework (https://github.com/haabe/mycelium). Standalone use will skip the canvas state, theory gates, and harness behavior the skill assumes. Install: /plugin install mycelium@haabe-mycelium."} |
Harms Check Skill
Design-time harm-to-users check — the safety-by-design lens the security/privacy/compliance gates structurally miss. Assumes the product works EXACTLY as designed. /threat-model (STRIDE) asks how an attacker breaks it; /privacy-check asks about personal data; neither asks: who could this harm when it works as intended, and how could a legitimate feature be misused?
This is the design-time front-end of the BVSSH Happier dimension: a manipulative or harmful design is Happier-negative by definition, and this gate catches it before /bvssh-check would only measure it post-hoc.
When to run (JiT — conditional, NOT universal)
Fires only when the product-shape warrants it:
- User-facing product/feature (real people use it), OR
- has persuasion / retention / conversion / cancellation / consent / pricing flows (the dark-pattern surface), OR
- touches vulnerable people (children, patients, financially- or otherwise at-risk).
If none apply (internal dev tooling, a library, a build script), SKIP — say so and move on. This is a NUDGE, never a hard block.
Workflow
1. Dark / deceptive patterns (Brignull) — does the design manipulate the user?
Check the design against the recognised, regulated catalog (deceptive.design; FTC / EU Digital Fairness Act / GDPR-consent):
Any hit = the design manipulates or coerces → Happier-NEGATIVE. Redesign for the honest default.
2. Consequence scanning (doteveryone) — intended AND unintended
- Intended consequences — which to amplify?
- Unintended consequences (assume it works as designed and scales) — which to mitigate?
- Who could this harm — including vulnerable users AND non-users / third parties / society?
- Who is least able to absorb the harm?
3. Foreseeable misuse (harms modeling) — weaponising a legitimate feature
- How could a bad actor use this feature-working-as-designed to harm someone (harassment, stalking, fraud, coercion)?
- What reasonably-foreseeable "unsupported uses" create harm?
Output
## Harms Check: [Feature/Product]
Scope trigger: [user-facing | persuasion/retention flow | vulnerable users | N/A — skipped]
### Deceptive patterns
| Pattern | Present? | Honest redesign |
|---------|----------|-----------------|
| ... | yes/no | ... |
### Consequences & foreseeable misuse
| Harm | Who (incl. non-users / vulnerable) | Working-as-designed or misuse | Mitigation |
|------|------------------------------------|-------------------------------|-----------|
| ... | ... | ... | ... |
### Happier verdict
[net-positive for the user | Happier-NEGATIVE — redesign]
### Recommendations (NUDGE — advice, not a block)
1. ...
Honest limits (scope guard)
This gate educates a builder who reached for a manipulative pattern without seeing the harm; it cannot stop a builder who deliberately wants to manipulate. It is a NUDGE keyed to product-shape — not a trust-&-safety / content-moderation apparatus. Online-content harms (CSAM, disinformation, hate speech) are out of scope and belong to specialised tooling, not Mycelium.
Decision Log (MANDATORY per G-P4)
APPEND a ### Harms Check entry to .claude/harness/decision-log.md with: the scope trigger, any deceptive patterns found, foreseeable-misuse / vulnerable-user harms, the Happier verdict, and mitigations accepted or waived.
Theory Citations
- Brignull: Deceptive (Dark) Patterns
- doteveryone: Consequence Scanning
- Microsoft: Harms Modeling (foreseeable misuse; vulnerable- and non-user harm)
- Smart: BVSSH — the "Happier" dimension (this gate is its design-time front-end)
- eSafety / WEF: Safety by Design (anticipate harm before it occurs)
