Coding standard for hook/compose-style tooling: never fail silently; parse defensively; gate writes by installed compatibility; and make transient failures self-healing. Diagnostics must only fail on real faults (e.g., stale markers), not normal in-flight states. Apply: 1) Normalize & parse defensively - Treat real-world inputs as messy: handle CRLF, trailing newlines, inline-empty forms, and whitespace. ```ts const t = toolResult.trim(); const m = t.match(/^Created the (.+) file\.$/); ``` - Prefer tolerant parsing for YAML-ish lists: support both `field: []` and block lists; don’t rely on a regex that only matches one form. 2) No silent no-ops: log “can’t apply” cases - If a contribution/merge can’t be applied because a target field is missing or unknown keys are encountered, write a drop/log entry (don’t just return unchanged). ```ts if (!hasField(content, 'produces')) { recordDrop(`contribution to ${target}: no 'produces:' field; adds dropped`); return content; } ``` - For declared-but-unimplemented surfaces, explicitly log that the key is deferred/ignored. 3) Compatibility gate writes by installed schema - If a new optional field may be unknown to older engine versions, probe the installed engine schema (or capability) before editing stage files, and skip+log when unsupported. 4) Make transient failures recoverable - Avoid “compile gate” logic that can turn a one-off failure into a permanent broken state. - Persist a retry marker on compile failure and clear it on success, or trigger recompilation when the merged artifacts aren’t present in the compiled graph. 5) Health/doctor outputs: fail only on real faults - When you detect an in-flight artifact (e.g., a compose marker), compute TTL freshness and set `pass` accordingly (fresh = pass, stale = fail). This prevents false red CI runs. ```ts const pass = ageMs <= COMPOSE_MARKER_TTL_MS; // fresh advisory ok results.push({ pass, message: pass ? 'fresh' : 'stale' }); ```