hindsight-bias

hindsight-bias is a skill for Claude Code, Codex from deciqAI/knowledge-skills. It costs 123 tokens per session (2,129 once invoked), scanned A, original, MIT.

A guide to hindsight bias, the tendency to remember an outcome as predictable after it has happened. It separates what was actually knowable before a decision from what became clear later.

In plain words
What is it for?
Use it to review decisions, investigate incidents, assess investors or managers, and challenge claims that an event was obvious in advance.
Why use it?
It reduces unfair blame in post-mortems and reviews by keeping the outcome from distorting judgment about the original decision.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to review decisions, investigate incidents, assess investors or managers, and challenge claims that an event was obvious in advance.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/deciqai/knowledge-skills/hindsight-bias
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.

Any agent
npx skills add deciqAI/knowledge-skills --skill hindsight-bias
Clone the repo
git clone --depth 1 https://github.com/deciqAI/knowledge-skills

Made for: Claude Code, Codex.

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 hindsight-bias

README.md
[![agentmods](https://agentmods.dev/badge/skills/deciqai/knowledge-skills/hindsight-bias/github.svg)](https://agentmods.dev/skills/deciqai/knowledge-skills/hindsight-bias)
Your own site
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/hindsight-bias"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/hindsight-bias/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 hindsight-bias

Your own site · 80×15
<a href="https://agentmods.dev/skills/deciqai/knowledge-skills/hindsight-bias"><img src="https://agentmods.dev/badge/skills/deciqai/knowledge-skills/hindsight-bias.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 123 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,129 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 pass 7 Sept 2026
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 $0.00123 $0.02129
Opus 5 $0.00062 $0.01064
Sonnet 5 $0.00025 $0.00426
Haiku 4.5 $0.00012 $0.00213

Measured 8d ago against content hash 0b4c5e9eed10, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

hindsight-bias 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 8d 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.

hindsight-bias/SKILL.md · 123 lines

How it starts

The opening of the file, as written. The whole thing — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Hindsight Bias

Overview

Hindsight bias — the "I knew it all along" effect — is the tendency, after learning an outcome, to misremember your prior judgment as having been closer to that outcome than it actually was. Fischhoff (1975) demonstrated three distinct components: memory distortion ("I said it would happen"), inevitability ("it had to happen"), and foreseeability ("anyone should have seen it"). Each requires a different countermeasure; the structural fix for all three is pre-commitment documentation.

Composes with probabilistic-thinking, premortem, confirmation-bias, and survivorship-bias.

When to Use

  • A post-mortem is becoming an exercise in blame for an "obviously foreseeable" outcome
  • Someone says "I knew this would happen" without contemporaneous records
  • A decision is being evaluated against its outcome rather than the information available when made
  • An investor, judge, or jury evaluates a past decision with knowledge of how it turned out
  • Someone calls a market move "obvious in retrospect" — e.g. the AI boom, AI capex buildout, or frontier-AI valuations were "clearly inevitable" / "anyone should have seen the AI adoption wave coming"

Not when: pre-commitment documentation exists and matches current memory; the goal is pattern-recognition from outcomes; the failure to predict was a genuine process failure with clear pre-outcome signals.

Coaching Novices (Adaptive Front Door)

  • Engine mode: user has a specific post-outcome narrative → run The Process directly.
  • Coach mode: user is unfamiliar or has no concrete case → guide step by step.

In Coach mode, respond one step at a time. Each [WAIT] is a hard stop — output only that step's question, then stop.

  1. One-line: before judging a past decision by its outcome, ask what was actually knowable in advance — check the contemporaneous record, not your current memory.
  2. Check fit against When to Use / When NOT to use. If records exist and match memory, bias is bounded.
  3. Elicit the specific outcome and the claim of foreseeability. What outcome happened? Who is being credited/blamed?

[WAIT — do not advance until user responds]

  1. Run The Process one step at a time: reconstruct the pre-outcome information set, decompose the three components, evaluate decision process vs. outcome.

[WAIT — do not advance until user responds]

  1. Close by naming the insight uncovered and the structural fix (decision journal, pre-mortem, blind post-mortem).

[WAIT — do not advance until user responds]

Read the full file on GitHub · 123 lines

Files

What ships with it

4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 8d ago First seen · 123 lines · 123 tokens per session scan A 0b4c5e9eed10

Subscribe to this mod's changes

hindsight-bias is a skill published in the GitHub repository deciqAI/knowledge-skills (10 stars, last pushed 10d ago), licensed MIT. It adds 123 tokens to every session and 2,129 once invoked, about $0.0006 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 2026-09-03.

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