occams-razor

name	occams-razor
description	Find the simplest explanation or solution that accounts for all known facts — use when there are multiple competing explanations and the simplest hasn't been tried first
argument-hint	[phenomenon or problem with multiple possible explanations]
user-invocable	true
license	MIT

Among competing explanations, identify the one that makes the fewest assumptions while still accounting for all observed evidence. Prefer simplicity, but not at the cost of explanatory power. 1. State the phenomenon or problem requiring explanation 2. List all known facts and observations that must be explained 3. Generate 3-5 candidate explanations of varying complexity 4. For each candidate, count the assumptions required 5. Check each candidate against all known facts — does it account for everything? 6. Select the simplest explanation that fits all facts 7. Identify what new evidence would distinguish between candidates

<output_format>

Occam's Razor Analysis: [Topic]

Observations to Explain

• [Fact 1]
• [Fact 2]

Candidate Explanations

Explanation	Assumptions	Fits all facts?
[Simple]	N	Yes/No
[Complex]	N	Yes/No

Simplest Sufficient Explanation

[The winner and why]

Distinguishing Evidence

[What would confirm or rule out alternatives] </output_format>

## Occam's Razor Analysis: API Response Time Increase

Observations to Explain

• P95 latency increased from 200ms to 800ms last Tuesday
• No code deployments that day
• Database CPU is normal
• Only affects the /search endpoint
• Traffic volume unchanged

Candidate Explanations

Explanation	Assumptions	Fits all facts?
Search index corrupted	1 (index can silently corrupt)	Yes
Upstream provider slowed down	1 (provider had an incident)	Yes — /search calls external API
DNS resolution intermittent	2 (DNS issue + only affects one endpoint)	Partial — why only /search?
Memory leak in search service	2 (leak exists + triggered Tuesday)	Partial — would worsen over time

Simplest Sufficient Explanation

Upstream search provider experienced degradation. This requires only one assumption (provider incident), explains why only /search is affected (it's the only endpoint calling that provider), and fits the Tuesday timing without needing a code change.

Distinguishing Evidence

Check the provider's status page for Tuesday incidents. If clean, run curl directly against the provider API to measure current latency. If provider is fast, re-examine the search index.

Key Instructions

• A simpler explanation that doesn't account for all known facts is not Occam's Razor — it's an incomplete explanation; simplicity cannot come at the cost of explanatory coverage.

Anti-Pattern Guards

1. Discarding evidence to achieve simplicity — the simplest explanation must fit all known facts; simplifying by ignoring inconvenient observations is not Occam's Razor.
2. Conflating common with simple — a common explanation requires fewer assumptions only if its commonness doesn't itself require additional assumptions to explain.

Handoff

Chainable to: 5-whys (to drill into the chosen explanation's root cause), map-vs-territory (to check whether the observations themselves are accurate)