Fluxmail

forward_email

Destructive

Forward an email to new recipients with a quoted original, "Fwd:" subject, and original attachments; add an optional comment above the forwarded content.

Instructions

Forward an email to new recipients: quoted original body, "Fwd:" subject, original attachments included unless includeAttachments=false. Optional comment appears above the forwarded content.

Input Schema

TableJSON Schema

Name	Required	Description
`cc`	No	Recipients, each "Name <a@x.com>" or "a@x.com"
`to`	Yes	Recipients, each "Name <a@x.com>" or "a@x.com"
`from`	No	Connected address or an available send-as address
`comment`	No	Comment above the forwarded message. Keep prose paragraphs on one continuous line and separate paragraphs with blank lines.
`accountId`	No	Account to operate on. Optional when exactly one account is connected.
`messageId`	Yes
`idempotencyKey`	Yes	Reuse this key when retrying the same forward
`includeAttachments`	No	Default true

Output Schema

TableJSON Schema

Name	Required	Description	Default
`data`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.11.1Oct 1, 2026
- removedOutput schema / $schema
```
Removed value: -"http://json-schema.org/draft-07/schema#"
```

Changed4 schema fields changedv0.11.0Sep 26, 2026

addedInput schema / properties / comment / description

Added value: +"Comment above the forwarded message. Keep prose paragraphs on one continuous line and separate paragraphs with blank lines."

addedInput schema / properties / idempotencyKey

Added value: +{
+  "description": "Reuse this key when retrying the same forward",
+  "pattern": "^[\\x21-\\x7e]{1,255}$",
+  "type": "string"
+}

changedInput schema / required

Previous value: -[
-  "messageId",
-  "to"
-]New value: +[
+  "idempotencyKey",
+  "messageId",
+  "to"
+]

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "additionalProperties": false,
+  "properties": {
+    "data": {
+      "additionalProperties": true,
+      "properties": {
+        "accountId": {
+          "type": "string"
+        },
+        "error": {
+          "additionalProperties": false,
+          "properties": {
+            "code": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "code"
+          ],
+          "type": "object"
+        },
+        "kind": {
+          "type": "string"
+        },
+        "operationId": {
+          "type": "string"
+        },
+        "result": {
+          "additionalProperties": true,
+          "properties": {
+            "id": {
+              "type": "string"
+            },
+            "threadId": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "id",
+            "threadId"
+          ],
+          "type": "object"
+        },
+        "scheduleId": {
+          "type": "string"
+        },
+        "status": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "operationId",
+        "accountId",
+        "kind",
+        "status"
+      ],
+      "type": "object"
+    }
+  },
+  "required": [
+    "data"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv0.9.0Sep 16, 2026

addedInput schema / properties / from

Added value: +{
+  "description": "Connected address or an available send-as address",
+  "format": "email",
+  "type": "string"
+}

First observedv0.1.0Jul 26, 2026

TDQS

A4/5.0

Behavior4/5

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

Annotations only supply destructiveHint=true, so the description carries the rest and does well: it discloses that the original body is quoted, the subject is prefixed with "Fwd:", attachments are included by default and can be suppressed, and where the comment lands. It does not mention auth/send-as requirements or idempotent-retry behavior, so it stops short of fully rich disclosure.

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

Conciseness5/5

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

Two sentences, front-loaded with the action and resource, then packed with only decision-relevant behavior. No filler or restatement of the tool name.

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

Completeness4/5

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

An output schema exists, so return values need not be explained, and the 8-parameter schema covers addressing and account selection. The description gives enough of the forward semantics to call it correctly; only auth/send-as context and retry semantics are absent.

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 coverage is 88%, so the schema already documents recipients, from, accountId, comment, and idempotencyKey. The description's notes on attachments and comment placement essentially restate the schema's own "Default true" and "Comment above the forwarded message" text, adding no new parameter-level meaning.

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?

States a specific verb ("Forward") and resource ("an email") and immediately enumerates the resulting behavior: quoted body, "Fwd:" subject, attachments carried over. Forwarding is inherently distinguishable from send_email/create_draft, so an agent can select it without opening a schema.

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

Usage Guidelines3/5

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

Usage is implied by the semantics (use this when an existing message must go to new recipients rather than composing fresh), but there is no explicit when-to-use statement, no mention of preview_send or send_email as alternatives, and no prerequisites such as send-as permissions.

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