Multi-item support is not enabled by type: array. The input may be scalar (subject, id, query) or a collection. Multi-item behavior comes from resolving/executing several items and returning per-item results[].

Agent               selects the operation; no business fan-out
  -> tools.yaml     declares the natural input contract: scalar OR collection
  -> tool_policies  confirmation/requires/pre-validation; no special multi-item syntax
  -> validator      resolves/canonicalizes and may expand one value into items[]
  -> MCP/workflow   executes 1 or N items and returns results[]
  -> framework      preserves per-item evidence and derives SUCCESS/PARTIAL_SUCCESS/FAILED
  -> presentation   reports each success/failure

Scalar pattern

tool_policies:
  cancelar_vas_avulso:
    operation_type: transactional
    require_confirmation: true
    requires:
      - subject
    pre_validation:
      enabled: true
      tool: validar_vas_subject
      fail_open: false

subject may represent one or many entities. The validator/workflow may expand it into canonical items[].

Explicit batch pattern

args_schema:
  items:
    type: array

This is supported, but it is an interface option, not a requirement.

Result contract

{
  "results": [
    {"name": "A", "success": true},
    {"name": "B", "success": false},
    {"name": "C", "success": true}
  ]
}

The runtime derives PARTIAL_SUCCESS and preserves the successful items.

For full details, read docs/MCP_MULTI_ITEM_DEVELOPER_GUIDE_en.md.