[ObjectIsAdvantag]

Added

• structuredContent in tools/call responses when outputSchema is declared.
  Per MCP spec 2025-06-18, when a tool declares an outputSchema the mock now
  populates structuredContent with the resolved JSON payload alongside the
  backward-compatible content text block. This applies to all three data
  sources: file overrides (--data), example selection, and Faker generation.
  Hosts and clients that consume the typed structuredContent path now receive
  data from the mock; text-only consumers are unaffected (no breaking change).

  Example response shape for a tool with outputSchema:

  {
    "content": [{ "type": "text", "text": "{\"sessionId\":\"mock-sessionId-001\",\"state\":\"active\",…}" }],
    "structuredContent": { "sessionId": "mock-sessionId-001", "state": "active", "totalQuestions": 42, "currentQuestion": 0 }
  }

• outputSchema-driven Faker generation.
  When a tool declares an outputSchema and no override or example is
  available, the Faker generator now produces data shaped by that schema
  (respecting types, enums, formats, and minimum/maximum constraints)
  rather than the generic success envelope. This gives a correct first-run
  experience for any tool with a declared output contract — no --data
  directory and no recording required.

• Optional debug validation of structuredContent against outputSchema.
  When --debug is set, the mock validates the resolved payload against the
  tool's outputSchema using Ajv and logs a warning to stderr if the data does
  not conform. This catches drift between authored fixtures and the declared
  output contract at design time without affecting normal operation.

• New test fixture tests/fixtures/mcpdesc/structured-output-server.mcpdesc.json:
  a dedicated mcpdesc with three tools (create-session, get-status,
  list-results) covering object outputSchema, no outputSchema, and array
  outputSchema respectively — used by the new integration suite.

• 7 new integration tests in
  tests/integration/structured-content.test.ts covering the Faker path and
  the --data override path for structuredContent emission and backward
  compatibility.

Fixed

• Replay matching for resources/read is now URI-aware. Recorded entries
  are keyed by concrete resource URI (resources/read:<uri>), enabling
  deterministic per-resource content replay (including template instances).
• Matched replay errors are surfaced for resources/read. A recorded
  error response is replayed as an error for the matching resource read,
  consistent with tools/call behavior.

Changed

• Replay authoring docs updated for method-specific matching rules.
  docs/authoring-replay-datasets.md now documents resources/read URI-aware
  keys, method-specific argument extraction, and the structuredContent field
  in hand-authored replay responses.