name: usability-is-existence description: Use when assessing feature completeness, auditing UX or onboarding, or judging whether a feature is "done" — especially gap analyses, SOTA comparisons, and first-run/cold-start reviews. metadata: version: "1.0.0"

Usability Is Existence

This skill defines a non-negotiable usability invariant:

A feature does not meaningfully exist unless at least one realistic interaction pathway allows a first-time user to discover and use it without prior knowledge.

This skill is authoritative and applies across UX, product, and implementation work.

Scope

This skill applies whenever an agent:

• Evaluates feature completeness
• Audits usability or UX
• Determines whether a feature “exists” or is “done”
• Performs gap analysis or SOTA comparison
• Assesses first-run or cold-start experiences

Core Rule (Invariant)

A feature MUST NOT be considered usable if:

• It can only be accessed via:
• Direct URLs
• Undocumented routes
• Internal knowledge
• Developer-only affordances
• It lacks any visible, inferable, or hinted UI entry point
• It requires prior awareness of its existence to be used

At least one valid pathway MUST:

• Start from visible UI elements
• Be reasonably discoverable by exploration
• Be achievable without reading documentation
• Be understandable in context

Consequences

If no such pathway exists:

• The feature is considered non-existent for users
• The feature MUST be flagged as:
• A UX defect
• An onboarding failure
• A discoverability gap

Technical existence alone is insufficient.

When NOT to Apply

• Internal/admin tooling deliberately URL- or permission-gated for a known audience
• APIs, CLIs, and SDKs — there, documentation IS the interaction pathway; judge doc discoverability instead
• Features explicitly scoped as hidden (feature-flagged betas, staged rollouts) — flag the gate, not the feature

Enforcement

If an agent claims a feature is “present” or “complete” without a valid user-discoverable pathway:

• The claim is invalid
• The agent MUST revise the assessment
• Downstream conclusions must not rely on the feature

Intent

This skill exists to prevent:

• “It’s there if you know where to click” products
• Hidden functionality masquerading as completeness
• Developer-centric definitions of usability
• Shipping features that only exist in theory