canvas-health

Canvas Health Check

Audit the canvas knowledge base for quality, consistency, and completeness. The canvas is Mycelium's source of truth -- its quality directly determines agent output quality (Raschka: "context quality = model quality").

When to Use

• Before any diamond phase transition (called automatically by /mycelium:diamond-assess)
• After a period of inactivity (>7 days since last canvas update)
• When agent output quality seems to degrade
• After onboarding a new team member (ensures canvas is self-explanatory)
• Proactively: run periodically to catch silent drift

Workflow

1. Load project configuration:

   • Read .claude/diamonds/active.yml for product_type and project_type
   • Read ${CLAUDE_PLUGIN_ROOT}/engine/canvas-guidance.yml for required/recommended/optional files per project type

2. Check file presence:

   • For each required canvas file: does it exist? Is it non-empty (>50 bytes)?
   • For each recommended canvas file: does it exist? Flag as gap if missing.
   • Report: N/M required files present, K recommended files missing

3. Check _meta blocks:

   • For each existing canvas file, check for _meta: block
   • Flag missing _meta blocks
   • Flag last_validated past the horizon for that file's category, per the "Which threshold applies to which canvas file" table in ${CLAUDE_PLUGIN_ROOT}/engine/evidence-decay.md (strategic 180d, technical feasibility 120d, user-needs/competitive/market 90d, delivery metrics 30d, regulatory 365d; unlisted files fall back to 90d).
   • SKIP any file whose _meta.applicability marks it inapplicable (a value starting n/a, or naming a product type this project is not, or saying "NOT actively used"). Added v0.90.0. Two dogfood canvases held ZERO evidence — every metric field null, the only non-null leaves False schema defaults — and already said so in their own _meta. They decayed on a 30-day horizon anyway, and the only way to silence that warning would have been to date a validation of a file nobody uses: the manufactured-validation move v0.89.0 removed last_updated to prevent. Precedents for the marker: dora-metrics.yml#sre (n/a-until-production) and dependency-pins.yml (scope: local). This replaced a flat 30-day rule in v0.89.0. That rule was the only staleness number in this skill grounded in nothing — step 7 below has always used the decay table — and on the dogfood repo it flagged 20 of 25 canvases, including a strategic file validated 46 days earlier against a 180-day horizon. A check that fires on 80% of a corpus trains its reader to skip it.
   • Flag version field missing or at 0