Environment: Linux; real T3 development server; Claude Code CLI with Haiku; synthetic replay history; no live database.
Side: head
Commit: 2f0c0474366e127d7f10c8e6606a364435cd9f94

Direct HTTP MCP calls (thread-bound agent session):
[
  {
    "label": "default",
    "arguments": {},
    "textCharacters": 8595,
    "jsonCharacters": 8595,
    "totalItems": 3234,
    "returnedItems": 10,
    "firstPosition": 2225,
    "lastPosition": 3134,
    "earlierPosition": 2225,
    "nextPosition": 3134,
    "hasMore": false,
    "chronological": true
  },
  {
    "label": "activity-1500",
    "arguments": {
      "view": "activity",
      "limit": 100,
      "maxCharsPerItem": 1500
    },
    "textCharacters": 29927,
    "jsonCharacters": 29927,
    "totalItems": 3234,
    "returnedItems": 47,
    "firstPosition": 3187,
    "lastPosition": 3233,
    "earlierPosition": 3187,
    "nextPosition": 3233,
    "hasMore": false,
    "chronological": true
  },
  {
    "label": "activity-1",
    "arguments": {
      "view": "activity",
      "limit": 100,
      "maxCharsPerItem": 1
    },
    "textCharacters": 30011,
    "jsonCharacters": 30011,
    "totalItems": 3234,
    "returnedItems": 54,
    "firstPosition": 3180,
    "lastPosition": 3233,
    "earlierPosition": 3180,
    "nextPosition": 3233,
    "hasMore": false,
    "chronological": true
  },
  {
    "label": "older-page",
    "arguments": {
      "view": "activity",
      "limit": 100,
      "maxCharsPerItem": 1500,
      "beforePosition": 3187
    },
    "textCharacters": 29908,
    "jsonCharacters": 29908,
    "totalItems": 3234,
    "returnedItems": 47,
    "firstPosition": 3140,
    "lastPosition": 3186,
    "earlierPosition": 3140,
    "nextPosition": 3186,
    "hasMore": true,
    "chronological": true
  },
  {
    "label": "explicit-start",
    "arguments": {
      "view": "activity",
      "limit": 100,
      "maxCharsPerItem": 1500,
      "afterPosition": -1
    },
    "textCharacters": 29619,
    "jsonCharacters": 29619,
    "totalItems": 3234,
    "returnedItems": 47,
    "firstPosition": 0,
    "lastPosition": 46,
    "earlierPosition": null,
    "nextPosition": 46,
    "hasMore": true,
    "chronological": true
  }
]

Actual Claude Code tool invocation and observed result:
{"type": "tool_use", "id": "toolu_01CyiGE8RdKByprHrxZJwmwj", "name": "mcp__proof__t3_thread_read", "input": {"threadId": "mcp:6e032cda-0997-48b1-81ea-a4e0283a18e8", "view": "activity", "limit": 100, "maxCharsPerItem": 1}, "caller": {"type": "direct"}}
Tool result delivered inline (full synthetic payload in head-activity-1.json).
The tool result was **not** saved to a file. It came back inline in the response.

The call returned 54 activity items (positions 3180 to 3233), with `hasMore: false`. The thread reports 3,234 items in total, so this is only the tail of the thread, not the full 100 I requested. The thread is still `running`. Each item's text was cut to a single character, as `maxCharsPerItem: 1` requested.