Harness Scope

Harness Scope

What this does for you

• One thing at a time — only one feature in_progress
• Done means observable — verification steps a human can follow
• Stable task list — the agent follows priorities, not rewrites the plan

Agents over-scope and under-finish (Lesson 07). Feature lists are harness primitives (Lesson 08): machine-readable boundaries the agent cannot ignore.

Scope rules

1. One active feature — only one with status: "in_progress"
2. Explicit priority — lower number = more urgent
3. Observable behavior — user_visible_behavior describes what the user sees
4. Verification as contract — concrete steps, not vague claims
5. Do not rewrite the list — adding features requires documented justification

Feature anatomy

{
  "id": "auth-001",
  "priority": 1,
  "area": "auth",
  "title": "Login with email and password",
  "user_visible_behavior": "User enters credentials and reaches the dashboard.",
  "status": "not_started",
  "verification": [
    "Open /login",
    "Enter valid credentials",
    "Verify redirect to /dashboard",
    "Verify error message with invalid credentials"
  ],
  "evidence": [],
  "notes": ""
}

Feature selection

At session start:

1. Filter status != "passing"
2. Sort by priority ASC
3. Pick the first
4. Set its status to "in_progress"
5. Work ONLY on that feature

Handling blockers

If a feature is blocked:

{
  "status": "blocked",
  "notes": "Requires Stripe API key — see issue #42"
}

Do not jump to another feature without documenting the blocker. Do not mark partial work as passing.

Support fixes

Changes outside the active feature scope only if:

• They unblock the current feature (narrow fix)
• They repair a broken verification baseline
• They are documented in notes or progress.md

Create feature_list from scratch

1. List user-visible features (not internal tasks)
2. Order by dependency → priority
3. Write verification[] as steps a human can follow
4. Set global rules in the JSON

Update workflow

Finish work on feature X:
  → Run verification[] for X
  → If pass: status="passing", evidence=[...]
  → If fail: fix or status="blocked"
  → Never: status="passing" without evidence

Anti-patterns

• Three features in_progress at once
• Vague verification: "works correctly"
• Deleting incomplete features from the list
• Implementing priority 5 while priority 1 is still pending

Templates

• templates/feature-list.json
• Schema: templates/feature-list.schema.json

Course reference

• Lesson 07: Why agents over-scope and under-finish
• Lesson 08: Why feature lists are harness primitives
• Project 04: Runtime feedback and scope control