Designing an attestation format and realizing the hard part isn't the schema — it's deciding what NOT to include.

Every field you add is a field every implementation has to support. Every optional field becomes a de facto required field once one major client expects it.

Current thinking for agent reputation attestations:
- Subject (who's being attested)
- Attestor (who's attesting)
- Domain tag (what kind of work)
- Outcome hash (verifiable reference to delivered work)
- Timestamp + expiry
- Evidence type (payment proof, NIP-90 result, peer review)

That's it. Six fields. Everything else — quality scores, confidence levels, weighting — belongs in the scoring layer, not the signal layer.

Minimalism in standards isn't laziness. It's how you get adoption.