laurigates/verify-before-plan

Verify Before Plan

A premise is anything the orchestrator's plan asserts about the world without having looked: "there are 41 SKILL.md files that need editing," "the deprecated endpoint still has callers," "build is green on main," "the agent must rewrite the manifest." Before a wave of parallel subagents fans out against that premise, verify it with a small read-only probe. A wrong premise propagates to every brief in the wave and wastes an entire wave's worth of work — restarting is the only honest salvage.

When to Use This Skill

| Use this skill when... | Skip when... | |---|---| | About to dispatch ≥2 parallel agents whose briefs cite a number, state, or path | Single-agent delegation — verify inline | | The premise was carried in from an earlier message and not re-checked this session | The premise was produced by a tool call earlier in this same session | | The user's report describes a symptom; the plan cites a cause | Waves entirely independent of repo state (e.g. brainstorming) | | The plan assumes a tool/library/agent does X based on its name or docs | The behaviour is covered by a passing test the wave will re-run | | The plan inherits a premise from another agent's return contract | The return contract already cites file:line evidence for the premise |

This skill sits before parallel-agent-dispatch in the dispatch sequence. parallel-agent-dispatch covers the contract; this skill covers the assumption the contract is built on.

The Verification Protocol

Step 1: Name the premise

State the load-bearing facts in one or two sentences, in the form the wave's briefs will reference. Numbers, paths, and "does X" claims must be explicit — "all the affected plugins" is not yet a premise.

Step 2: Pick the cheapest verifier

| Premise shape | Verifier | |---|---| | File count / "N occurrences of …" | Glob or Grep -c directly from the main thread | | "Does this tool/agent do X?" | Dispatch one read-only general-purpose agent: "Report what <thing> actually does, with file:line citations" | | "Build is green / artefact exists" | One Bash call (gh pr checks, ls path, git log --branches) | | "User's bug is X" | Read the failing log; do not patch the symptom | | Manifest / counter snapshot | Read the file and quote the relevant lines |

Inline the verifier if it is one to three tool calls. Use a one-shot investigation agent only when the answer requires multi-file synthesis.

Step 3: Verifier return contract

The verifier — whether inline calls or a dispatched agent — must report:

## Premise
<one-line restatement of what is being checked>

## Evidence
- file:line — <quoted finding>
- file:line — <quoted finding>

## Verdict
- confirmed | refuted | partial: <what changed>
- exact count / value: <N>
- sample paths: <up to 5>

## Implicit assumptions surfaced
- <assumptions the verifier had to make to answer>
- empty is fine — section must exist

Refuse to dispatch the wave until this report exists. "I'll check while dispatching" loses the salvage argument before it starts.

Step 4: Diff verdict against premise

If confirmed, dispatch as planned. If refuted or partial, revise the plan: shrink the file scope, re-allocate per-agent IDs, drop agents that no longer have work, re-write the brief that cites the refuted fact. Only then dispatch.

Anti-patterns

| Premise | How it fails | Verifier | |---|---|---| | "There are 41 SKILL.md files needing edits" | Actual was 28 — some plugins have no skills; 13 agents had empty briefs | Glob("**/SKILL.md") then count | | "git-repo-agent supports X" (from the name) | Name ≠ behaviour; agent did not implement X | Read agents/git-repo-agent/SKILL.md | | "The user says the bug is X" | Bug was a config typo two layers up; the X patch did nothing | Read the failing log / repro | | "The plan says clear stuck Jobs" | Real root cause was an IdP password mismatch in ConfigMap; jobs were a symptom | Re-spelunk with one read-only agent | | "Manifest counter is at WO-012" | Counter was bumped by a coworker mid-session | Read the manifest as the last act before allocation | | "Build is green" (from morning standup) | Broke an hour ago; one wave-member tripped over the failing step | gh pr checks or gh run list | | "All callers of the deprecated API are gone" | Two remained in a vendored copy outside the search root | Grep with a wide-enough path |

The unifying pattern: the premise was true at some past moment, but the current session has not confirmed it. Time is the silent invalidator.

Composition

| With … | Slot it in by … | |---|---| | parallel-agent-dispatch | Verify before the worktree-preflight; preflight assumes the file scope is right | | wave-based-dispatch | Verify per wave — a Phase-1 wave's return contract is a premise for Phase 2 | | exclusive-lock-dispatch | Verify the lock-holder list is current; locks come and go | | agent-teams | The Lead Preflight Checklist's "file-scope and pin-budget" entries are premises |

Quick Reference

Orchestrator checklist (before any parallel dispatch)

• [ ] Premise named in one or two sentences with numbers and paths
• [ ] Verifier picked (inline call ≤ 3, otherwise one read-only agent)
• [ ] Verifier return contract followed (Premise / Evidence / Verdict / Assumptions)
• [ ] Verdict confirmed — or plan revised before dispatch
• [ ] Implicit assumptions logged for the wave's briefs

Common mistakes

| Mistake | Correct approach | |---|---| | "Based on the name, X probably does Y" | Dispatch a read-only probe; cite file:line | | "The user says the bug is X, so we patch X" | Read the failing repro before any patch | | "The plan's remediation is X" | Verify the plan's premise; remediations inherit its truth-value | | Verifying after dispatch ("I'll check while they work") | Verify first — re-running a wave costs more than the probe | | Skipping the Verdict line — just summarising | The wave's briefs need a copy-pasteable fact, not a narrative |

Related

• parallel-agent-dispatch — the dispatch contract whose preflight this skill protects
• wave-based-dispatch — per-wave premise verification fits cleanly between phases
• exclusive-lock-dispatch — lock inventory is itself a premise
• .claude/rules/regression-testing.md — landing a verifier as a script check when a premise-failure recurs
• Motivating evidence: issue #1283 — aggregate wrong_approach and initial_misdiagnosis signals across 284 sessions