outlook-mcp

outlook_send_with_attachments

Destructive

Send an email with file attachments, auto-switching to upload sessions for files over 3MB. Paths resolve inside the configured attachments directory.

Instructions

Send an email with file attachments; auto-switches to upload-session for files >3MB.

attachment_paths resolve inside the configured attachments directory (attachments_dir, an attachments folder in the settings directory by default) — a bare filename is looked up there, and a path outside it is refused. attachments: inline files [{name, content_base64, content_type?}], up to 3MB each. Pass reply_to to route replies to a different address.

Input Schema

Name	Required	Default
`cc`	No
`to`	Yes
`bcc`	No
`body`	Yes
`is_html`	No
`subject`	Yes
`reply_to`	No
`importance`	No	normal
`attachments`	No
`attachment_paths`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed31 schema fields changedv1.30.2Oct 30, 2026
- removedInput schema / properties / attachment_paths / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / attachment_paths / default
```
Removed value: -null
```
- addedInput schema / properties / attachment_paths / items
```
Added value: +{
+  "type": "string"
+}
```
- removedInput schema / properties / attachment_paths / title
```
Removed value: -"Attachment Paths"
```
- addedInput schema / properties / attachment_paths / type
```
Added value: +"array"
```
- removedInput schema / properties / attachments / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "additionalProperties": {
-        "type": "string"
-      },
-      "type": "object"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / attachments / default
```
Removed value: -null
```
- addedInput schema / properties / attachments / items
```
Added value: +{
+  "additionalProperties": {
+    "type": "string"
+  },
+  "type": "object"
+}
```
- removedInput schema / properties / attachments / title
```
Removed value: -"Attachments"
```
- addedInput schema / properties / attachments / type
```
Added value: +"array"
```
- removedInput schema / properties / bcc / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / bcc / default
```
Removed value: -null
```
- addedInput schema / properties / bcc / items
```
Added value: +{
+  "type": "string"
+}
```
- removedInput schema / properties / bcc / title
```
Removed value: -"Bcc"
```
- addedInput schema / properties / bcc / type
```
Added value: +"array"
```
- removedInput schema / properties / body / title
```
Removed value: -"Body"
```
- removedInput schema / properties / cc / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / cc / default
```
Removed value: -null
```
- addedInput schema / properties / cc / items
```
Added value: +{
+  "type": "string"
+}
```
- removedInput schema / properties / cc / title
```
Removed value: -"Cc"
```
- addedInput schema / properties / cc / type
```
Added value: +"array"
```
- removedInput schema / properties / importance / title
```
Removed value: -"Importance"
```
- removedInput schema / properties / is_html / title
```
Removed value: -"Is Html"
```
- removedInput schema / properties / reply_to / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / reply_to / default
```
Removed value: -null
```
- addedInput schema / properties / reply_to / items
```
Added value: +{
+  "type": "string"
+}
```
- removedInput schema / properties / reply_to / title
```
Removed value: -"Reply To"
```
- addedInput schema / properties / reply_to / type
```
Added value: +"array"
```
- removedInput schema / properties / subject / title
```
Removed value: -"Subject"
```
- removedInput schema / properties / to / title
```
Removed value: -"To"
```
- removedInput schema / title
```
Removed value: -"outlook_send_with_attachmentsArguments"
```

Changed6 schema fields changedv1.28.0Oct 25, 2026

addedInput schema / properties / attachment_paths / anyOf

Added value: +[
+  {
+    "items": {
+      "type": "string"
+    },
+    "type": "array"
+  },
+  {
+    "type": "null"
+  }
+]

addedInput schema / properties / attachment_paths / default
```
Added value: +null
```
removedInput schema / properties / attachment_paths / items
```
Removed value: -{
-  "type": "string"
-}
```
removedInput schema / properties / attachment_paths / type
```
Removed value: -"array"
```

addedInput schema / properties / attachments

Added value: +{
+  "anyOf": [
+    {
+      "items": {
+        "additionalProperties": {
+          "type": "string"
+        },
+        "type": "object"
+      },
+      "type": "array"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Attachments"
+}

changedInput schema / required

Previous value: -[
-  "to",
-  "subject",
-  "body",
-  "attachment_paths"
-]New value: +[
+  "to",
+  "subject",
+  "body"
+]

First observedv1.11.0Jun 10, 2026

TDQS

A3.7/5.0

Behavior4/5

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

The annotations already declare this as non-read-only and destructive, and the description adds meaningful behavioral context: automatic upload-session switching for large files, path resolution confined to the attachments directory, refusal of outside paths, and a 3MB inline-attachment limit. It does not mention return behavior or authentication requirements, but it adds substantial beyond the annotations.

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?

The description is front-loaded with the core action and then gives attachment-specific constraints in compact, purpose-driven sentences. There is little wasted text, and each sentence adds operational detail.

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

Completeness3/5

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

For a 10-parameter send tool with no output schema and no annotation-level detail beyond destructive hints, the description covers the most complex attachment behaviors but leaves several parameters and the return/result shape undocumented. It is adequate for attachment handling but not fully complete.

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 0%, so the description carries the burden for parameter meaning. It explains the tricky parameters well—attachment_paths resolution, inline attachments structure and size limit, and reply_to routing—but does not cover importance values, is_html behavior, or the conventional recipient/body fields.

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

Purpose4/5

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

The description states a specific verb and resource: send an email with file attachments. It clearly distinguishes itself from the general send tool by emphasizing attachments, though it does not explicitly name outlook_send_message as the no-attachment alternative.

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 attachment focus and the >3MB upload-session behavior, but the description does not explicitly say when to use this versus outlook_send_message, outlook_create_draft, or outlook_send_draft. The attachment-source rules are helpful but are constraints rather than alternative-selection guidance.

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

Deploy Server

outlook_send_with_attachments

Instructions

Input Schema

Schema Changelog

TDQS

Other Tools