Mailrith Email Marketing

Update a broadcast

broadcasts_update

DestructiveIdempotent

Updates an existing Broadcast draft. Scheduled, running, completed, and failed Broadcasts cannot be changed here. Before changing a scheduled Broadcast, read it by ID and retain its scheduled_at in the current task only. If the saved time is no longer safely in the future, ask the user for a new time before unscheduling. Otherwise unschedule it, apply the update, reschedule it for the same time, and verify both status and scheduled_at. If the update fails after unscheduling, restore the unchanged Broadcast to the same future time when possible. If the schedule cannot be restored, leave it as a Draft and immediately report that it will not send; never choose a replacement time without the user. Effect: workspace-change. Retry after reading the current resource state. Permission: broadcasts:write. API reference: https://mailrith.com/developers/api-reference.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`body`	Yes	The exact JSON request body defined by the Mailrith public API contract.
`broadcast_id`	Yes	The broadcast identifier.

Output Schema

TableJSON Schema

Name	Required	Description
`error`	No
`response`	No
`request_id`	Yes	The stable correlation ID for this MCP tool invocation.
`operation_id`	Yes	The stable Mailrith public API operation ID.

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

Changed10 schema fields changedSep 3, 2026

changedInput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedInput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello from Mailrith.",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedInput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello from Mailrith.",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

removedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / $ref
```
Removed value: -"#/$defs/BroadcastEmailDocument"
```
addedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / allOf
```
Added value: +[
+  {
+    "$ref": "#/$defs/BroadcastEmailDocument"
+  }
+]
```

addedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / description

Added value: +"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

addedInput schema / $defs / BroadcastUpdateRequest / properties / subject / description

Added value: +"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedOutput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedOutput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello from Mailrith.",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedOutput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello from Mailrith.",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

Changed10 schema fields changedSep 3, 2026

changedInput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes."

changedInput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello from Mailrith.",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedInput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello from Mailrith.",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

addedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / $ref
```
Added value: +"#/$defs/BroadcastEmailDocument"
```
removedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / allOf
```
Removed value: -[
-  {
-    "$ref": "#/$defs/BroadcastEmailDocument"
-  }
-]
```

removedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / description

Removed value: -"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

removedInput schema / $defs / BroadcastUpdateRequest / properties / subject / description

Removed value: -"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedOutput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes."

changedOutput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello from Mailrith.",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedOutput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello from Mailrith.",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

Changed10 schema fields changedAug 17, 2026

changedInput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedInput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello from Mailrith.",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedInput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello from Mailrith.",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

removedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / $ref
```
Removed value: -"#/$defs/BroadcastEmailDocument"
```
addedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / allOf
```
Added value: +[
+  {
+    "$ref": "#/$defs/BroadcastEmailDocument"
+  }
+]
```

addedInput schema / $defs / BroadcastUpdateRequest / properties / body_document / description

Added value: +"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

addedInput schema / $defs / BroadcastUpdateRequest / properties / subject / description

Added value: +"For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedOutput schema / $defs / BroadcastEmailDocument / description

Previous value: -"A structured email document. The root node must use type `doc` and contain supported block nodes."New value: +"A structured email document. The root node must use type `doc` and contain supported block nodes. For Subscriber personalization in email subjects and body text nodes, use Mailrith bracket tokens such as [Subscriber_Name, fallback=\"friend\"] or [Subscriber_Email, fallback=\"\"]. Before using a custom field, call custom_fields_list or custom_fields_get and copy its personalization_token exactly. Do not use Handlebars-style variables such as {{ subscriber.name }}; Mailrith sends them as literal text."

changedOutput schema / $defs / BroadcastEmailDocument / example / content

Previous value: -[
-  {
-    "content": [
-      {
-        "text": "Hello from Mailrith.",
-        "type": "text"
-      }
-    ],
-    "type": "paragraph"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+        "type": "text"
+      }
+    ],
+    "type": "paragraph"
+  }
+]

changedOutput schema / $defs / BroadcastEmailDocument / examples

Previous value: -[
-  {
-    "content": [
-      {
-        "content": [
-          {
-            "text": "Hello from Mailrith.",
-            "type": "text"
-          }
-        ],
-        "type": "paragraph"
-      }
-    ],
-    "type": "doc"
-  }
-]New value: +[
+  {
+    "content": [
+      {
+        "content": [
+          {
+            "text": "Hello [Subscriber_Name, fallback=\"friend\"].",
+            "type": "text"
+          }
+        ],
+        "type": "paragraph"
+      }
+    ],
+    "type": "doc"
+  }
+]

First observedJul 30, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate a write and destructive operation, but the description goes far beyond by explaining the exact effect on scheduled broadcasts (unschedule/update/reschedule), the recovery behavior if the schedule cannot be restored, and the mandatory reporting to the user. It also mentions the workspace-change effect and the need to retry after reading current resource state, providing rich behavioral context not available in structured fields.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is longer than ideal, but every sentence carries critical procedural information about handling scheduled broadcasts and failure recovery. It is front-loaded with the core purpose and then logically flows into constraints and detailed workflow. The only minor drawback is the density of instructions in a single paragraph, which could be slightly restructured for readability, but it is still appropriately sized for the tool's complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's complex behavior around updating drafts and rescheduling, the description is remarkably complete. It covers all relevant edge cases: which states are disallowed, how to handle scheduled broadcasts, what to do on failure, and the user reporting requirement. The existence of an output schema means return values need not be described, and the description even includes permission and API reference links, making it self-sufficient.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, meaning broadcast_id and body both have descriptions (e.g., 'The broadcast identifier' and 'The exact JSON request body defined by the Mailrith public API contract'). The tool description adds some usage context around broadcast_id (e.g., read by ID for scheduled broadcasts) but does not elaborate on the body fields, leaving that to the nested schema. This is adequate but does not exceed the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with 'Updates an existing Broadcast draft,' clearly stating the action and target. It distinguishes this tool from siblings by explicitly listing which broadcast states cannot be changed here (scheduled, running, completed, failed), making it stand apart from broadcasts_create, broadcasts_schedule, and similar tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit when-to-use guidance: it is for drafts only, and for scheduled broadcasts it prescribes a specific unschedule-update-reschedule workflow, including reading the broadcast by ID first and asking the user for a new time if the saved time is unsafe. It also tells the user what to do if the update fails after unscheduling, effectively covering alternatives and exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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TDQS

A3.8/5.0

Disambiguation5/5

Every tool is prefixed by its resource and targets a unique action, so there is no real overlap between tools. Even similar operations like preflight, preview_journey, and send_test are clearly separated by resource and described with distinct effects.

Naming Consistency5/5

All tools follow a consistent `resource_action` snake_case pattern, e.g., broadcasts_create, subscribers_upsert, sequences_update_status. Custom verbs like cancel, unschedule, and preview_journey still fit the same predictable convention.

Tool Count1/5

55 tools is an extreme count for a single MCP server, making it difficult for an agent to efficiently discover and choose among the surface. While each tool appears justified, the size suggests the API should be split into focused servers by resource domain.

Completeness3/5

The broadcast, automation, sequence, and subscriber workflows are well covered with lifecycle operations. However, custom fields and segments only have read/list/preview operations with no create, update, or delete, and several resources lack delete endpoints, leaving notable gaps for full lifecycle management.

Update a broadcast

Input Schema

Output Schema

Schema Changelog

TDQS

Glama MCP Gateway

TDQS

Resources