whiteboard: Skill for Claude Code

.claude/skills/diagnosis-evidence/SKILL.md

diagnosis-evidence is a skill for Claude Code from kamiazya/whiteboard. It costs 57 tokens per session (2,080 once invoked), scanned A, original, Apache-2.0.

A procedure for proving that debugging evidence actually tests the failure or fix being discussed. It applies to failing tests, continuous-integration failures, flaky tests, mutation checks, and manual verification.

In plain words
What is it for?
It is for choosing observations that could disprove a diagnosis, checking which tests exercised a changed line, and verifying that reported fixes or mutations were truly tested.
Why use it?
It prevents misleading conclusions, such as treating an unrelated test failure as proof that a code change was caught.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is kamiazya/whiteboard's own configuration. It tells Claude Code how to work on whiteboard itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything whiteboard configures →

Part of the whiteboard plugin — 22 skills, 18 agents, 3 hooks shipped together

Reuse

Borrowing it

Nothing to install: this file belongs to kamiazya/whiteboard. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/kamiazya/whiteboard/main/.claude/skills/diagnosis-evidence/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/kamiazya/whiteboard

Made for: Claude Code.

Or install whiteboard, the plugin that ships this one along with the rest of its 22 skills, 18 agents, 3 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for diagnosis-evidence

README.md
[![agentmods](https://agentmods.dev/badge/skills/kamiazya/whiteboard/diagnosis-evidence/github.svg)](https://agentmods.dev/skills/kamiazya/whiteboard/diagnosis-evidence)
Your own site
<a href="https://agentmods.dev/skills/kamiazya/whiteboard/diagnosis-evidence"><img src="https://agentmods.dev/badge/skills/kamiazya/whiteboard/diagnosis-evidence/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for diagnosis-evidence

Your own site · 80×15
<a href="https://agentmods.dev/skills/kamiazya/whiteboard/diagnosis-evidence"><img src="https://agentmods.dev/badge/skills/kamiazya/whiteboard/diagnosis-evidence.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,080 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 2 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Tool Misuse · line 111
    Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.
    Fix: Limit tool chaining depth and validate the output of each tool before passing it to the next. Require explicit user approval for multi-step chains.
  • high Tool Misuse · line 124
    Tool calls are chained to bypass individual safety checks or escalate capabilities beyond what any single tool call would allow.
    Fix: Limit tool chaining depth and validate the output of each tool before passing it to the next. Require explicit user approval for multi-step chains.
How audits are shown
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 5.1 $0.00057 $0.02080
Opus 5 $0.00028 $0.01040
Sonnet 5 $0.00011 $0.00416
Haiku 4.5 $0.00006 $0.00208

Measured 9d ago against content hash 0cac7d0a47c6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

diagnosis-evidence 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 9d 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.

.claude/skills/diagnosis-evidence/SKILL.md · 180 lines

How it starts

The opening of the file, as written. The whole thing — 180 lines — stays where its author put it; the contents beside it link to each section on GitHub.

A diagnosis is only as good as the proof that you measured what you think

measured-change is about instrumenting a CHANGE whose effect you cannot see. This is about the step before: a FAILURE you are explaining, or a fix you are calling verified. Both fail the same way — a number arrives, it looks like evidence, and nothing in it says what was actually exercised.

Every rule below cost a wrong public conclusion in one session.

Pick an observation that could REFUTE the claim

The rule the others are instances of. Three wrong conclusions in one session shared this shape: the observation taken was CONSISTENT with the claim and could not have contradicted it, so it read as confirmation while testing nothing.

  • A mutant reported failed 1 test and was read as killed. The failing test was a flake, in a file the mutated line cannot reach; three full runs of the mutated build all passed. One failure is equally consistent with killed and with a flake — only WHICH test failed tells them apart.
  • A survivor at elements[0]?.attrs?.[name] was hand-checked by mutating both optional chains. It went red, and the reported mutant was only one of them. Mutating more than what was reported can only produce red; red then says nothing about the reported mutant.
  • okSecond was called unreachable after measuring that zeroBendFacingFirst never returns two pairs. True, and about a different question: the two pushes are mutually exclusive, so a single pair can arrive from either. Measured on the branch that actually answers the claim, 242 of 7893 firings came from the non-dominant one.

So before running the observation, name the outcome that would make you say the claim is WRONG. If no outcome of this observation would, you are about to confirm rather than test — take the discriminator instead: the failing test's NAME rather than the count, the reported mutant's exact line and columns rather than the expression around it, the branch the claim is about rather than the one beside it.

Read the full file on GitHub · 180 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. 9d ago Changed · +28 lines 0cac7d0a47c6
  2. 12d ago First seen · 152 lines · 57 tokens per session scan A 7524441a8ef7

Subscribe to this mod's changes

diagnosis-evidence is a skill published in the GitHub repository kamiazya/whiteboard (6 stars, last pushed today), licensed Apache-2.0. It adds 57 tokens to every session and 2,080 once invoked, about $0.0003 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 2026-08-31.

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