# MCP tool reference

1 callable tools.

Use tools/call at https://mcp.schedulerzero.com/mcp with the exact tool name and arguments below. The /tools/ paths in this view are documentation identifiers, not HTTP endpoints. Request execution is disabled for this reference.

Inputs are shown for personal API keys (bound) and for OAuth/delegated agents. Output schemas describe MCP structuredContent: native objects pass through; arrays, scalars and null use a data wrapper. Text content retains the native JSON result.

[Connect a client](/mcp/connect) · [Authentication and authorization](/authentication) · [Generated auth guide](/auth.md) · [Download tool catalog](/mcp-catalog.json) · [Agent documentation](/llms.txt)

## cancel_operation

Request cancellation of a durable operation where its kind supports cancellation.

Use to stop queued or running work the agent no longer needs; the result reports whether cancellation took.

Cancellation is not a rollback; completed work and already-sent side effects stay done.

Scopes: agent:operations:cancel, agent:operations:read

Risk: write; confirmation: none; idempotency: supported.

### Input schema (personal API key)

```json
{
  "type": "object",
  "properties": {
    "operationId": {
      "type": "string",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
      "format": "uuid"
    }
  },
  "required": [
    "operationId"
  ],
  "patternProperties": {
    "^(?!(?:operationId)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "operationId"
        ]
      }
    ]
  }
}
```

### Input schema (OAuth / delegated agent)

```json
{
  "type": "object",
  "properties": {
    "operationId": {
      "type": "string",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
      "format": "uuid"
    }
  },
  "required": [
    "operationId"
  ],
  "patternProperties": {
    "^(?!(?:operationId)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "anyOf": [
      {
        "type": "string",
        "enum": [
          "operationId"
        ]
      }
    ]
  }
}
```

### Output schema (structuredContent)

```json
{
  "type": "object",
  "properties": {
    "id": {
      "type": "string",
      "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
      "format": "uuid"
    },
    "cancellation": {
      "type": "string",
      "enum": [
        "supported",
        "requested",
        "terminal"
      ]
    },
    "state": {
      "type": "string",
      "enum": [
        "queued",
        "running",
        "waiting_for_user",
        "succeeded",
        "partially_succeeded",
        "failed",
        "canceled",
        "canceling"
      ]
    }
  },
  "required": [
    "id",
    "cancellation",
    "state"
  ],
  "patternProperties": {
    "^(?!(?:id|cancellation|state)$)[\\s\\S]*$": false
  },
  "additionalProperties": true,
  "propertyNames": {
    "type": "string",
    "enum": [
      "id",
      "cancellation",
      "state"
    ]
  }
}
```

### Underlying API operations

- `agent.cancelOperation`: `POST /agent/operations/:operationId/cancel`
- `agent.getOperation`: `GET /agent/operations/:operationId`