# 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)

## send_test_email

Sends a real test email from an inbox, optionally through a campaign, or a warmup test send.

When asked to send a test email to verify inbox configuration or warmup.

For campaign sends to leads — that is a campaign launch.

Obtain the user's explicit authorization before invoking a write or destructive action. This is a client interaction requirement, not a server-issued approval token.

Scopes: inbox:update, inbox:warmup_manage

Risk: costly; confirmation: explicit; idempotency: supported.

### Input schema (personal API key)

```json
{
  "type": "object",
  "anyOf": [
    {
      "type": "object",
      "properties": {
        "workspaceId": {
          "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})$",
          "format": "uuid"
        },
        "action": {
          "type": "string",
          "enum": [
            "send"
          ]
        },
        "inboxId": {
          "type": "string",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
          "format": "uuid"
        },
        "payload": {
          "type": "object",
          "properties": {
            "to": {
              "$ref": "#/$defs/EmailAddress"
            },
            "campaignId": {
              "$ref": "#/$defs/ShortText"
            },
            "subject": {
              "type": "string",
              "maxLength": 10000
            },
            "body": {
              "type": "string",
              "maxLength": 1000000
            },
            "bodyContentType": {
              "type": "string",
              "enum": [
                "html",
                "plain"
              ]
            }
          },
          "required": [
            "to"
          ],
          "patternProperties": {
            "^(?!(?:to|campaignId|subject|body|bodyContentType)$)[\\s\\S]*$": false
          },
          "additionalProperties": true,
          "propertyNames": {
            "type": "string",
            "enum": [
              "to",
              "campaignId",
              "subject",
              "body",
              "bodyContentType"
            ]
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "inboxId",
        "payload"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId|action|inboxId|payload)$)[\\s\\S]*$": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "type": "string",
        "enum": [
          "workspaceId",
          "action",
          "inboxId",
          "payload"
        ]
      }
    },
    {
      "type": "object",
      "properties": {
        "workspaceId": {
          "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})$",
          "format": "uuid"
        },
        "action": {
          "type": "string",
          "enum": [
            "warmup_send"
          ]
        },
        "inboxId": {
          "type": "string",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
          "format": "uuid"
        },
        "payload": {
          "type": "object",
          "properties": {
            "to": {
              "$ref": "#/$defs/EmailAddress"
            }
          },
          "required": [
            "to"
          ],
          "patternProperties": {
            "^(?!(?:to)$)[\\s\\S]*$": false
          },
          "additionalProperties": true,
          "propertyNames": {
            "anyOf": [
              {
                "type": "string",
                "enum": [
                  "to"
                ]
              }
            ]
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "inboxId",
        "payload"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId|action|inboxId|payload)$)[\\s\\S]*$": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "type": "string",
        "enum": [
          "workspaceId",
          "action",
          "inboxId",
          "payload"
        ]
      }
    }
  ],
  "$defs": {
    "EmailAddress": {
      "type": "string",
      "minLength": 3,
      "maxLength": 320,
      "pattern": "^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$"
    },
    "ShortText": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256
    }
  }
}
```

### Input schema (OAuth / delegated agent)

```json
{
  "type": "object",
  "properties": {
    "workspaceId": {
      "type": "string",
      "format": "uuid",
      "description": "Target Workspace UUID. Call list_workspaces to enumerate the Workspaces this credential may access, then pass the chosen id here."
    }
  },
  "required": [
    "workspaceId"
  ],
  "anyOf": [
    {
      "type": "object",
      "properties": {
        "workspaceId": {
          "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})$",
          "format": "uuid"
        },
        "action": {
          "type": "string",
          "enum": [
            "send"
          ]
        },
        "inboxId": {
          "type": "string",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
          "format": "uuid"
        },
        "payload": {
          "type": "object",
          "properties": {
            "to": {
              "$ref": "#/$defs/EmailAddress"
            },
            "campaignId": {
              "$ref": "#/$defs/ShortText"
            },
            "subject": {
              "type": "string",
              "maxLength": 10000
            },
            "body": {
              "type": "string",
              "maxLength": 1000000
            },
            "bodyContentType": {
              "type": "string",
              "enum": [
                "html",
                "plain"
              ]
            }
          },
          "required": [
            "to"
          ],
          "patternProperties": {
            "^(?!(?:to|campaignId|subject|body|bodyContentType)$)[\\s\\S]*$": false
          },
          "additionalProperties": true,
          "propertyNames": {
            "type": "string",
            "enum": [
              "to",
              "campaignId",
              "subject",
              "body",
              "bodyContentType"
            ]
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "inboxId",
        "payload"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId)$)[\\s\\S]*?(?:^(?!(?:workspaceId|action|inboxId|payload)$)[\\s\\S]*$)": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "anyOf": [
          {
            "type": "string",
            "enum": [
              "workspaceId",
              "action",
              "inboxId",
              "payload"
            ]
          },
          {
            "enum": [
              "workspaceId"
            ]
          }
        ]
      }
    },
    {
      "type": "object",
      "properties": {
        "workspaceId": {
          "type": "string",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
          "format": "uuid"
        },
        "action": {
          "type": "string",
          "enum": [
            "warmup_send"
          ]
        },
        "inboxId": {
          "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})$",
          "format": "uuid"
        },
        "payload": {
          "type": "object",
          "properties": {
            "to": {
              "$ref": "#/$defs/EmailAddress"
            }
          },
          "required": [
            "to"
          ],
          "patternProperties": {
            "^(?!(?:to)$)[\\s\\S]*$": false
          },
          "additionalProperties": true,
          "propertyNames": {
            "anyOf": [
              {
                "type": "string",
                "enum": [
                  "to"
                ]
              }
            ]
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "inboxId",
        "payload"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId)$)[\\s\\S]*?(?:^(?!(?:workspaceId|action|inboxId|payload)$)[\\s\\S]*$)": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "anyOf": [
          {
            "type": "string",
            "enum": [
              "workspaceId",
              "action",
              "inboxId",
              "payload"
            ]
          },
          {
            "enum": [
              "workspaceId"
            ]
          }
        ]
      }
    }
  ],
  "$defs": {
    "EmailAddress": {
      "type": "string",
      "minLength": 3,
      "maxLength": 320,
      "pattern": "^[^\\s@]+@[^\\s@]+\\.[^\\s@]+$"
    },
    "ShortText": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256
    }
  }
}
```

### Output schema (structuredContent)

```json
{
  "$defs": {
    "OpaqueId": {
      "type": "string",
      "minLength": 1,
      "maxLength": 512
    },
    "HttpUrl": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048,
      "pattern": "^https?:\\/\\/[^\\s/$.?#][^\\s]*$"
    },
    "HttpResourcePath": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048,
      "pattern": "^\\/[A-Za-z0-9._~!$&'()*+,;=:@/%-]*$"
    },
    "UtcDateTimeEncoded": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{3}Z$"
    },
    "NonEmptyString": {
      "type": "string",
      "minLength": 1,
      "maxLength": 4096
    }
  },
  "type": "object",
  "anyOf": [
    {
      "allOf": [
        {
          "anyOf": [
            {
              "type": "object",
              "properties": {
                "success": {
                  "type": "boolean",
                  "enum": [
                    true
                  ]
                },
                "messageId": {
                  "anyOf": [
                    {
                      "$ref": "#/$defs/OpaqueId"
                    },
                    {
                      "type": "null"
                    }
                  ]
                },
                "threadId": {
                  "anyOf": [
                    {
                      "$ref": "#/$defs/OpaqueId"
                    },
                    {
                      "type": "null"
                    }
                  ]
                }
              },
              "required": [
                "success",
                "messageId",
                "threadId"
              ],
              "patternProperties": {
                "^(?!(?:success|messageId|threadId)$)[\\s\\S]*$": false
              },
              "additionalProperties": true,
              "propertyNames": {
                "type": "string",
                "enum": [
                  "success",
                  "messageId",
                  "threadId"
                ]
              }
            },
            {
              "type": "object",
              "properties": {
                "runId": {
                  "$ref": "#/$defs/OpaqueId"
                },
                "requestId": {
                  "$ref": "#/$defs/OpaqueId"
                },
                "operation": {
                  "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})$",
                      "format": "uuid"
                    },
                    "statusUrl": {
                      "anyOf": [
                        {
                          "$ref": "#/$defs/HttpUrl"
                        },
                        {
                          "$ref": "#/$defs/HttpResourcePath"
                        }
                      ]
                    },
                    "state": {
                      "type": "string",
                      "enum": [
                        "queued",
                        "running",
                        "waiting_for_user",
                        "succeeded",
                        "partially_succeeded",
                        "failed",
                        "canceled",
                        "canceling"
                      ]
                    },
                    "acceptedAt": {
                      "$ref": "#/$defs/UtcDateTimeEncoded"
                    },
                    "progress": {
                      "type": "object",
                      "properties": {
                        "completed": {
                          "type": "integer",
                          "minimum": 0
                        },
                        "total": {
                          "type": "integer",
                          "minimum": 0
                        },
                        "message": {
                          "$ref": "#/$defs/NonEmptyString"
                        }
                      },
                      "required": [
                        "completed"
                      ],
                      "patternProperties": {
                        "^(?!(?:completed|total|message)$)[\\s\\S]*$": false
                      },
                      "additionalProperties": true,
                      "propertyNames": {
                        "type": "string",
                        "enum": [
                          "completed",
                          "total",
                          "message"
                        ]
                      }
                    },
                    "canCancel": {
                      "type": "boolean"
                    }
                  },
                  "required": [
                    "id",
                    "statusUrl",
                    "state",
                    "acceptedAt",
                    "canCancel"
                  ],
                  "patternProperties": {
                    "^(?!(?:id|statusUrl|state|acceptedAt|progress|canCancel)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "type": "string",
                    "enum": [
                      "id",
                      "statusUrl",
                      "state",
                      "acceptedAt",
                      "progress",
                      "canCancel"
                    ]
                  }
                }
              },
              "required": [
                "runId",
                "requestId",
                "operation"
              ],
              "patternProperties": {
                "^(?!(?:runId|requestId|operation)$)[\\s\\S]*$": false
              },
              "additionalProperties": true,
              "propertyNames": {
                "type": "string",
                "enum": [
                  "runId",
                  "requestId",
                  "operation"
                ]
              }
            }
          ]
        },
        {
          "type": "object"
        }
      ]
    },
    {
      "type": "object",
      "properties": {
        "data": {
          "allOf": [
            {
              "anyOf": [
                {
                  "type": "object",
                  "properties": {
                    "success": {
                      "type": "boolean",
                      "enum": [
                        true
                      ]
                    },
                    "messageId": {
                      "anyOf": [
                        {
                          "$ref": "#/$defs/OpaqueId"
                        },
                        {
                          "type": "null"
                        }
                      ]
                    },
                    "threadId": {
                      "anyOf": [
                        {
                          "$ref": "#/$defs/OpaqueId"
                        },
                        {
                          "type": "null"
                        }
                      ]
                    }
                  },
                  "required": [
                    "success",
                    "messageId",
                    "threadId"
                  ],
                  "patternProperties": {
                    "^(?!(?:success|messageId|threadId)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "type": "string",
                    "enum": [
                      "success",
                      "messageId",
                      "threadId"
                    ]
                  }
                },
                {
                  "type": "object",
                  "properties": {
                    "runId": {
                      "$ref": "#/$defs/OpaqueId"
                    },
                    "requestId": {
                      "$ref": "#/$defs/OpaqueId"
                    },
                    "operation": {
                      "type": "object",
                      "properties": {
                        "id": {
                          "type": "string",
                          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
                          "format": "uuid"
                        },
                        "statusUrl": {
                          "anyOf": [
                            {
                              "$ref": "#/$defs/HttpUrl"
                            },
                            {
                              "$ref": "#/$defs/HttpResourcePath"
                            }
                          ]
                        },
                        "state": {
                          "type": "string",
                          "enum": [
                            "queued",
                            "running",
                            "waiting_for_user",
                            "succeeded",
                            "partially_succeeded",
                            "failed",
                            "canceled",
                            "canceling"
                          ]
                        },
                        "acceptedAt": {
                          "$ref": "#/$defs/UtcDateTimeEncoded"
                        },
                        "progress": {
                          "type": "object",
                          "properties": {
                            "completed": {
                              "type": "integer",
                              "minimum": 0
                            },
                            "total": {
                              "type": "integer",
                              "minimum": 0
                            },
                            "message": {
                              "$ref": "#/$defs/NonEmptyString"
                            }
                          },
                          "required": [
                            "completed"
                          ],
                          "patternProperties": {
                            "^(?!(?:completed|total|message)$)[\\s\\S]*$": false
                          },
                          "additionalProperties": true,
                          "propertyNames": {
                            "type": "string",
                            "enum": [
                              "completed",
                              "total",
                              "message"
                            ]
                          }
                        },
                        "canCancel": {
                          "type": "boolean"
                        }
                      },
                      "required": [
                        "id",
                        "statusUrl",
                        "state",
                        "acceptedAt",
                        "canCancel"
                      ],
                      "patternProperties": {
                        "^(?!(?:id|statusUrl|state|acceptedAt|progress|canCancel)$)[\\s\\S]*$": false
                      },
                      "additionalProperties": true,
                      "propertyNames": {
                        "type": "string",
                        "enum": [
                          "id",
                          "statusUrl",
                          "state",
                          "acceptedAt",
                          "progress",
                          "canCancel"
                        ]
                      }
                    }
                  },
                  "required": [
                    "runId",
                    "requestId",
                    "operation"
                  ],
                  "patternProperties": {
                    "^(?!(?:runId|requestId|operation)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "type": "string",
                    "enum": [
                      "runId",
                      "requestId",
                      "operation"
                    ]
                  }
                }
              ]
            },
            {
              "not": {
                "type": "object"
              }
            }
          ]
        }
      },
      "required": [
        "data"
      ],
      "additionalProperties": false
    }
  ]
}
```

### Underlying API operations

- `inboxes.sendTestEmail`: `POST /v1/workspaces/:workspaceId/inboxes/:inboxId/test-email`
- `inboxWarmupSettings.sendTest`: `POST /v1/workspaces/:workspaceId/inboxes/:inboxId/warmup-settings/test`