spec: `get_creative_delivery` uses inline `pagination.total` while every other list response uses `PaginationResponse.total_count`

[bokelley]

Context

Surfaced during @adcp/sdk bridge work (adcontextprotocol/adcp-client#1772). The protocol-expert review noted:

get_creative_delivery defines pagination inline with a total field while the rest of 3.0.11 uses PaginationResponse.total_count. The bridge correctly uses total — but this is inconsistent with the rest of the spec.

Evidence

• schemas/cache/3.0.11/bundled/creative/get-creative-delivery-response.json line ~5519-5540 defines pagination INLINE as {has_more, cursor, total} (note the field name total, no _count)
• schemas/cache/3.0.11/core/pagination-response.json is the shared PaginationResponse schema with fields {has_more, cursor, total_count}
• Other list responses that use the shared schema via $ref:
  • list_creatives
  • get_signals
  • list_property_lists
  • list_collection_lists
  • list_content_standards
  • All consistently use total_count

get_creative_delivery is the only list response in 3.0.11 with the inline divergent shape.

Likely cause

Drafting drift. Probably an early-spec inline definition that was never refactored to $ref: PaginationResponse when the shared schema was introduced.

Suggested fix

Replace the inline pagination block in get-creative-delivery-response.json with:

"pagination": {
  "$ref": "../core/pagination-response.json"
}

This standardizes the field name (total_count everywhere) and reduces maintenance surface — pagination semantics live in one place.

Migration impact

Buyer-facing breaking change if any adopter has already implemented get_creative_delivery reading pagination.total. Worth a brief grep in adopter repos before the rename. Conservative alternative: keep total as an alias for one minor version, deprecate in changelog, remove in next major.

Adopter context

When the SDK implements pagination-drift recomputation in its bridge layer, every bridge has to know the right field name. Inconsistencies create per-tool special-casing that should be straight schema lookup. We worked around it for now (if (typeof pagination.total === 'number') instead of total_count), but the spec drift is the real fix.

Related

• feat(testing): signals/creative-delivery/creative-features seeded bridges (#1755 phase 3) adcp-client#1772 (the SDK bridge that surfaced this)
• cleanup: list_authorized_properties references in spec/skills/storyboards (replaced by get_adcp_capabilities) #4574 (the broader retired-tools cleanup tracker, may want to bundle this fix into the same sweep)