Feasibility Probe

Validates a spec by attempting a time-boxed prototype. Produces a viability report that feeds sprint planning with evidence-based estimates.

Decision Checklist

Before running the probe:

1. Is the spec approved (status: approved)? If NO -> abort, spec needs review first.
2. Does the spec have testable acceptance criteria? If NO -> abort, spec is too vague.
3. Are external dependencies documented? If NO -> warn, will mock everything.
4. Is the budget appropriate for spec size? If >20 requirements -> suggest splitting.
5. Has this spec been probed before? If YES -> show previous score, ask if re-probe.

Parameters

Param	Required	Default	Description
spec_path	Yes	-	Path to the spec file
budget_minutes	No	15	Max time for prototype attempt (time-box, orthogonal to model thinking)

Thinking budget (SE-067 — Opus 4.7 adaptive): Fixed budget_tokens removed. Opus 4.7 uses adaptive thinking — the model decides when and how much to think per step. Simple probes get fast responses, complex reasoning steps get deep thought. Over a multi-step probe run this adds up to lower token usage vs the old fixed 50000-token budget with no quality loss.

To steer thinking rate when needed, append to the probe prompt:

• More thinking: "Think carefully and step-by-step; this is harder than it looks."
• Less thinking: "Prioritize responding quickly rather than thinking deeply."

Execution Flow

1. Read spec -> extract requirements checklist
2. Launch feasibility-probe agent (Task) with budget
3. Agent attempts prototype in /tmp/
4. Agent writes report to output/feasibility/
5. Parse score and route:
   - >= 80: "Ready for sprint planning"
   - 40-79: "Recommend decomposition" + suggestions
   - < 40:  "Requires research" + escalate to human
6. Store report in memory for model-upgrade-audit tracking

Output

Report saved to: output/feasibility/{spec-id}-probe.yaml

Summary shown in chat:

Feasibility: {score}/100 | {resolved}/{total} requirements
Complexity: {level} | Time: {minutes}m
Blocking: {list of blocked sections}
Recommendation: {action}

Integration Points

• Pre-sprint: Run on all specs before sprint planning
• SDD pipeline: Optional gate between spec-approve and dev-session
• Memory: Results stored for longitudinal tracking
• Model audit: SPEC-002 consumes historical probe data

Scoring Formula

score = (resolved * 100 + partial * 50) / total_requirements
complexity = score >= 90 ? "trivial"
           : score >= 70 ? "low"
           : score >= 50 ? "medium"
           : score >= 30 ? "high"
           : "requires-research"