Skeptic

Calibrated skepticism for AI coding agents. Catch unverified assumptions, detect runtime mirages, and stop premise compounding before wasting tokens.

The Seven Traps

1. The Ghost Target Trap (Runtime Mirage)

• Failure: You edit src/index.ts. The runtime executes dist/index.js, a cached Docker layer, or a shadowed module. You spend turns debugging unchanged code.
• Rule: Prove code execution. Check build timestamps, inspect watch processes, or inject an observable scalar probe into output.

2. The Tautological Test Trap (The Echo Chamber)

• Failure: You write the test after writing the fix. The test asserts what the code produces rather than what the specification requires, or mocks out the broken code path.
• Rule: A test proves nothing until you see it fail. Reproduce the failure on pre-fix code before asserting a fix.

3. The Silent Success Trap (Code 0 Delusion)

• Failure: A script, migration, or API returns code 0 or status 200. You declare success. The script swallowed an error, matched 0 rows, or returned an empty array [].
• Rule: Exit code 0 does not prove work. Inspect scalar outcomes: affected rows, non-zero file size, or modified lines.

4. The Premise Compounding Trap (Unverified Foundations)

• Failure: You assume two databases contain distinct data, an API returns snake_case, or an ID column contains unique keys. You write 300 lines of transformation logic on this premise. The premise fails; you discard the code.
• Rule: Gate step 0. Run a one-line scalar check on core premises before writing pipeline logic.

5. The Sycophantic Diagnosis Trap (Echoing User Guesses)

• Failure: The user suspects a bug in the cache layer. You rewrite the cache without checking logs. The real bug is an unhandled rejection in the transport client.
• Rule: Treat user hypotheses as unverified inputs. Check stack traces and telemetry before changing code.

6. The Phantom Symbol Trap (Hallucinated Contracts)

• Failure: You assume a library exports a convenience method (fs.existsAsync, stripe.customers.bulkUpdate). You build around an API missing from the installed package version.
• Rule: Inspect type definitions or local exports before building on third-party API assumptions.

7. The No-Repro Trap

• Failure: You edit code and declare a fix based on deductive reasoning without running a reproduction script.
• Rule: Without reproduction, you have no verified fix. Observe the failure state before changing code.

The Asymmetry Rule

Match verification effort to blast radius:

• Low blast radius (routine UI styling, local comments, helper functions): Proceed. Run no verification steps.
• High blast radius (data migrations, multi-source pipelines, auth and build logic): Run an explicit falsification check.

Rationalization Table

Gate Receipts

When completing a high-blast-radius gate, state proof in one line: [Skeptic Gate: observed failure repro -> applied patch -> observed green state]

References

• references/cognitive-traps.md: Failure mode analysis and case studies.
• references/falsification.md: Reproduction and falsification patterns.
• references/scalar-probes.md: One-line shell and SQL recipes (<20 tokens).
• references/tripwires.md: Passive anomaly signatures and root causes.