P3: Each Harness Mitigates A Failure Mode¶

Each harness mitigates a specific LLM failure mode.

A harness exists because it reduces a named failure mode. The BlockContract.mitigates_failure_modes field links the implementation to the failure-mode registry.

Why it matters¶

This is the architectural justification for the harness existing at all. A harness that does not mitigate any failure mode is not earning its complexity over a raw LLM call — you could have called the model directly. Requiring a declared, registered failure mode keeps the component library honest about why each piece is there.

How it is enforced¶

C2: Mitigates failure modes requires at least one entry for any allow-listed harness, and every entry must resolve to a registered code in the failure-mode registry. The link appears on both the harness page and the failure-mode page; the mitigation map shows the full grid.

Primary gate: C2: Mitigates failure modes.