# 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)

## manage_blocklist

List, add, or remove blocked senders for a workspace; entries are normalized to lowercase addresses or bare domains.

Use to audit or edit the suppression list that keeps a workspace from mailing blocked addresses or domains.

Entries must be email addresses or bare DNS domains — URLs, wildcards, and paths are rejected. Removal is destructive.

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: blocklist:read, blocklist:create, blocklist:delete

Risk: write; 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})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "list"
              ]
            }
          ]
        },
        "search": {
          "$ref": "#/$defs/ShortText"
        },
        "cursor": {
          "$ref": "#/$defs/Cursor"
        },
        "limit": {
          "type": "integer",
          "minimum": 1,
          "maximum": 100
        }
      },
      "required": [
        "workspaceId",
        "action"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId|action|search|cursor|limit)$)[\\s\\S]*$": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "type": "string",
        "enum": [
          "workspaceId",
          "action",
          "search",
          "cursor",
          "limit"
        ]
      }
    },
    {
      "type": "object",
      "properties": {
        "workspaceId": {
          "type": "string",
          "pattern": "^([0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[1-8][0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}|00000000-0000-0000-0000-000000000000|[fF]{8}-[fF]{4}-[fF]{4}-[fF]{4}-[fF]{12})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "add"
              ]
            }
          ]
        },
        "entries": {
          "type": "array",
          "prefixItems": [
            {
              "$ref": "#/$defs/BlockedEmailEntryEncoded"
            }
          ],
          "minItems": 1,
          "items": {
            "$ref": "#/$defs/BlockedEmailEntryEncoded"
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "entries"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId|action|entries)$)[\\s\\S]*$": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "type": "string",
        "enum": [
          "workspaceId",
          "action",
          "entries"
        ]
      }
    },
    {
      "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})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "remove"
              ]
            }
          ]
        },
        "entry": {
          "$ref": "#/$defs/BlockedEmailEntryEncoded"
        }
      },
      "required": [
        "workspaceId",
        "action",
        "entry"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId|action|entry)$)[\\s\\S]*$": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "type": "string",
        "enum": [
          "workspaceId",
          "action",
          "entry"
        ]
      }
    }
  ],
  "$defs": {
    "ShortText": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256
    },
    "Cursor": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048
    },
    "BlockedEmailEntryEncoded": {
      "type": "string"
    }
  }
}
```

### 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})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "list"
              ]
            }
          ]
        },
        "search": {
          "$ref": "#/$defs/ShortText"
        },
        "cursor": {
          "$ref": "#/$defs/Cursor"
        },
        "limit": {
          "type": "integer",
          "minimum": 1,
          "maximum": 100
        }
      },
      "required": [
        "workspaceId",
        "action"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId)$)[\\s\\S]*?(?:^(?!(?:workspaceId|action|search|cursor|limit)$)[\\s\\S]*$)": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "anyOf": [
          {
            "type": "string",
            "enum": [
              "workspaceId",
              "action",
              "search",
              "cursor",
              "limit"
            ]
          },
          {
            "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})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "add"
              ]
            }
          ]
        },
        "entries": {
          "type": "array",
          "prefixItems": [
            {
              "$ref": "#/$defs/BlockedEmailEntryEncoded"
            }
          ],
          "minItems": 1,
          "items": {
            "$ref": "#/$defs/BlockedEmailEntryEncoded"
          }
        }
      },
      "required": [
        "workspaceId",
        "action",
        "entries"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId)$)[\\s\\S]*?(?:^(?!(?:workspaceId|action|entries)$)[\\s\\S]*$)": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "anyOf": [
          {
            "type": "string",
            "enum": [
              "workspaceId",
              "action",
              "entries"
            ]
          },
          {
            "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})$",
          "format": "uuid"
        },
        "action": {
          "anyOf": [
            {
              "type": "string",
              "enum": [
                "remove"
              ]
            }
          ]
        },
        "entry": {
          "$ref": "#/$defs/BlockedEmailEntryEncoded"
        }
      },
      "required": [
        "workspaceId",
        "action",
        "entry"
      ],
      "patternProperties": {
        "^(?!(?:workspaceId)$)[\\s\\S]*?(?:^(?!(?:workspaceId|action|entry)$)[\\s\\S]*$)": false
      },
      "additionalProperties": true,
      "propertyNames": {
        "anyOf": [
          {
            "type": "string",
            "enum": [
              "workspaceId",
              "action",
              "entry"
            ]
          },
          {
            "enum": [
              "workspaceId"
            ]
          }
        ]
      }
    }
  ],
  "$defs": {
    "ShortText": {
      "type": "string",
      "minLength": 1,
      "maxLength": 256
    },
    "Cursor": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048
    },
    "BlockedEmailEntryEncoded": {
      "type": "string"
    }
  }
}
```

### Output schema (structuredContent)

```json
{
  "$defs": {
    "BlockedEmailEntryEncoded": {
      "type": "string"
    },
    "UtcDateTimeEncoded": {
      "type": "string",
      "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{3}Z$"
    },
    "Cursor": {
      "type": "string",
      "minLength": 1,
      "maxLength": 2048
    }
  },
  "type": "object",
  "anyOf": [
    {
      "allOf": [
        {
          "anyOf": [
            {
              "type": "object",
              "properties": {
                "items": {
                  "type": "array",
                  "items": {
                    "type": "object",
                    "properties": {
                      "entry": {
                        "$ref": "#/$defs/BlockedEmailEntryEncoded"
                      },
                      "createdAt": {
                        "$ref": "#/$defs/UtcDateTimeEncoded"
                      },
                      "updatedAt": {
                        "$ref": "#/$defs/UtcDateTimeEncoded"
                      }
                    },
                    "required": [
                      "entry",
                      "createdAt",
                      "updatedAt"
                    ],
                    "patternProperties": {
                      "^(?!(?:entry|createdAt|updatedAt)$)[\\s\\S]*$": false
                    },
                    "additionalProperties": true,
                    "propertyNames": {
                      "type": "string",
                      "enum": [
                        "entry",
                        "createdAt",
                        "updatedAt"
                      ]
                    }
                  }
                },
                "nextCursor": {
                  "anyOf": [
                    {
                      "$ref": "#/$defs/Cursor"
                    },
                    {
                      "type": "null"
                    }
                  ]
                }
              },
              "required": [
                "items",
                "nextCursor"
              ],
              "patternProperties": {
                "^(?!(?:items|nextCursor)$)[\\s\\S]*$": false
              },
              "additionalProperties": true,
              "propertyNames": {
                "type": "string",
                "enum": [
                  "items",
                  "nextCursor"
                ]
              }
            },
            {
              "type": "object",
              "properties": {
                "inserted": {
                  "type": "integer",
                  "minimum": 0,
                  "maximum": 9007199254740991
                }
              },
              "required": [
                "inserted"
              ],
              "patternProperties": {
                "^(?!(?:inserted)$)[\\s\\S]*$": false
              },
              "additionalProperties": true,
              "propertyNames": {
                "anyOf": [
                  {
                    "type": "string",
                    "enum": [
                      "inserted"
                    ]
                  }
                ]
              }
            },
            {
              "type": "object",
              "properties": {
                "deleted": {
                  "anyOf": [
                    {
                      "type": "boolean",
                      "enum": [
                        true
                      ]
                    }
                  ]
                }
              },
              "required": [
                "deleted"
              ],
              "patternProperties": {
                "^(?!(?:deleted)$)[\\s\\S]*$": false
              },
              "additionalProperties": true,
              "propertyNames": {
                "anyOf": [
                  {
                    "type": "string",
                    "enum": [
                      "deleted"
                    ]
                  }
                ]
              }
            }
          ]
        },
        {
          "type": "object"
        }
      ]
    },
    {
      "type": "object",
      "properties": {
        "data": {
          "allOf": [
            {
              "anyOf": [
                {
                  "type": "object",
                  "properties": {
                    "items": {
                      "type": "array",
                      "items": {
                        "type": "object",
                        "properties": {
                          "entry": {
                            "$ref": "#/$defs/BlockedEmailEntryEncoded"
                          },
                          "createdAt": {
                            "$ref": "#/$defs/UtcDateTimeEncoded"
                          },
                          "updatedAt": {
                            "$ref": "#/$defs/UtcDateTimeEncoded"
                          }
                        },
                        "required": [
                          "entry",
                          "createdAt",
                          "updatedAt"
                        ],
                        "patternProperties": {
                          "^(?!(?:entry|createdAt|updatedAt)$)[\\s\\S]*$": false
                        },
                        "additionalProperties": true,
                        "propertyNames": {
                          "type": "string",
                          "enum": [
                            "entry",
                            "createdAt",
                            "updatedAt"
                          ]
                        }
                      }
                    },
                    "nextCursor": {
                      "anyOf": [
                        {
                          "$ref": "#/$defs/Cursor"
                        },
                        {
                          "type": "null"
                        }
                      ]
                    }
                  },
                  "required": [
                    "items",
                    "nextCursor"
                  ],
                  "patternProperties": {
                    "^(?!(?:items|nextCursor)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "type": "string",
                    "enum": [
                      "items",
                      "nextCursor"
                    ]
                  }
                },
                {
                  "type": "object",
                  "properties": {
                    "inserted": {
                      "type": "integer",
                      "minimum": 0,
                      "maximum": 9007199254740991
                    }
                  },
                  "required": [
                    "inserted"
                  ],
                  "patternProperties": {
                    "^(?!(?:inserted)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "anyOf": [
                      {
                        "type": "string",
                        "enum": [
                          "inserted"
                        ]
                      }
                    ]
                  }
                },
                {
                  "type": "object",
                  "properties": {
                    "deleted": {
                      "anyOf": [
                        {
                          "type": "boolean",
                          "enum": [
                            true
                          ]
                        }
                      ]
                    }
                  },
                  "required": [
                    "deleted"
                  ],
                  "patternProperties": {
                    "^(?!(?:deleted)$)[\\s\\S]*$": false
                  },
                  "additionalProperties": true,
                  "propertyNames": {
                    "anyOf": [
                      {
                        "type": "string",
                        "enum": [
                          "deleted"
                        ]
                      }
                    ]
                  }
                }
              ]
            },
            {
              "not": {
                "type": "object"
              }
            }
          ]
        }
      },
      "required": [
        "data"
      ],
      "additionalProperties": false
    }
  ]
}
```

### Underlying API operations

- `blockedEmails.list`: `GET /v1/workspaces/:workspaceId/settings/blocked-emails`
- `blockedEmails.add`: `POST /v1/workspaces/:workspaceId/settings/blocked-emails`
- `blockedEmails.remove`: `DELETE /v1/workspaces/:workspaceId/settings/blocked-emails/:entry`