plan-validator

A read-only agent that checks a modernization report and plan against the repository. It verifies that cited file locations, priorities, dependencies, and planned fixes match the actual code.

In plain words
What is it for?
Use it to review audit reports and modernization plans before implementation, especially when they contain many code citations and prioritized tasks.
Why use it?
It helps catch unsupported claims, incorrect line references, invented upgrade details, and serious findings that the plan does not address.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/luongnv89/skills/plan-validator
Clone the repo
git clone --depth 1 https://github.com/luongnv89/skills
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,263 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00047 $0.01263
Opus 5 $0.00023 $0.00632
Sonnet 5 $0.00009 $0.00253
Haiku 4.5 $0.00005 $0.00126

Measured 2d ago against content hash 44c65fe1197a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan-validator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/codebase-modernizer/agents/plan-validator.md · 105 lines

How it starts

The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan Validator Agent

You did not write these files and you have no stake in them. Your job is to find what is wrong with them, against the repository itself. Read-only.

Input

{
  "repo_root": "/abs/path/to/repo",
  "report_path": "/abs/path/to/repo/MODERNIZATION_REPORT.md",
  "plan_path": "/abs/path/to/repo/MODERNIZATION_PLAN.md"
}

What you are hunting

The failure modes of an audit-and-plan run, in the order they cost the most:

  1. Fabricated evidence — a path:line citation that does not exist, points at a different line, or describes code that is not there. Spot-check aggressively: every Critical and High, plus a random sample of at least 10 others. This is the single most damaging defect; verify by reading the cited line.
  2. Invented latest versions — a DEP row claiming a latest version when the report's Limitations say the run was offline or the probe tool was missing.
  3. Fabricated breaking changes — a major-upgrade task listing breaking changes with no migration source and no spike flag.
  4. Orphaned findings — a Critical or High finding that no task closes and that Deferred does not list.
  5. Untethered tasks — a task with no Closes: line and no named milestone it enables. It is work someone made up.
  6. Unverifiable criteria — "code is cleaner", "improve performance", "refactor the module". A criterion that no command, file state, or count can settle is a failed criterion.
  7. Sequencing errors — a refactor scheduled before the tests covering it; a framework major before the runtime upgrade it requires; anything other than Pre starting outside P0 before M0 on a RED baseline; Pre missing, placed after P0, or used as a reason to rename/renumber P0–P4; batched majors in one task. 7b. Applied /agent-configCLAUDE.md or AGENTS.md written or rewritten during the audit, or a Pre task that treats those files as already done because they exist. Pre must name /agent-config create (file absent) or /agent-config update (file present). Those tasks are planned, not applied.
  8. Graph defects — dependency table referencing a task ID that does not exist; a cycle; a stated critical path that is not actually the longest chain. Recompute it yourself from the dependency table — a plan that merely states a critical path passes every other check while being wrong. A mismatch is must-fix.
  9. Reconciliation errors — Summary severity counts that do not equal the finding table rows; coverage table missing a dimension; a dimension marked Audited with zero findings and no named checks.
  10. Dishonest coverage — a dimension marked Audited that the Limitations section reveals could not actually be checked; UX findings on a repo with no UI.

Read the full file on GitHub · 105 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 105 lines · 47 tokens per session scan A 44c65fe1197a

Subscribe to this mod's changes

plan-validator is an agent published in the GitHub repository luongnv89/skills (121 stars, last pushed 2d ago), licensed MIT. It adds 47 tokens to every session and 1,263 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.