outlook-mcp

outlook_update_event

Destructive

Update fields on an existing Outlook calendar event via partial patch; only supplied fields change, including times, attendees, recurrence, or all-day status.

Instructions

Update fields on an existing event (partial patch — only provided fields change).

recurrence takes the same shapes as outlook_create_event and converts a single event into a series, or replaces an existing series' pattern. Omit it to leave any recurrence alone; pass remove_recurrence=True to turn a series back into a single event, keeping the first occurrence's time (the two are mutually exclusive). attendees REPLACES the whole guest list (Graph has no add-one operation) and sends invitations to everyone on it plus cancellations to anyone dropped — pass the full intended list; [] removes everyone. is_all_day REQUIRES start and end in the same call, both on midnight boundaries. Patching a time keeps the zone the event is anchored in; pass timezone (with start and end) to re-anchor it somewhere else. A start, end or recurrence patch to a series with edited or deleted occurrences is refused, since Graph would discard them. Omitting an argument leaves it unchanged, so False and [] are instructions, not absences. show_as is Outlook's "Show as" — same values as outlook_create_event — and patches on its own; unlike is_all_day it needs nothing resent alongside it. key patches on its own too.

Input Schema

Name	Required	Description	Default
`end`	No
`key`	No
`body`	No
`start`	No
`show_as`	No
`subject`	No
`event_id`	Yes
`location`	No
`timezone`	No
`attendees`	No
`is_all_day`	No
`recurrence`	No
`remove_recurrence`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed47 schema fields changedv1.30.2Oct 30, 2026
- removedInput schema / properties / attendees / anyOf
```
Removed value: -[
-  {
-    "items": {
-      "type": "string"
-    },
-    "type": "array"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / attendees / default
```
Removed value: -null
```
- addedInput schema / properties / attendees / items
```
Added value: +{
+  "type": "string"
+}
```
- removedInput schema / properties / attendees / title
```
Removed value: -"Attendees"
```
- addedInput schema / properties / attendees / type
```
Added value: +"array"
```
- removedInput schema / properties / body / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / body / default
```
Removed value: -null
```
- removedInput schema / properties / body / title
```
Removed value: -"Body"
```
- addedInput schema / properties / body / type
```
Added value: +"string"
```
- removedInput schema / properties / end / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / end / default
```
Removed value: -null
```
- removedInput schema / properties / end / title
```
Removed value: -"End"
```
- addedInput schema / properties / end / type
```
Added value: +"string"
```
- removedInput schema / properties / event_id / title
```
Removed value: -"Event Id"
```
- removedInput schema / properties / is_all_day / anyOf
```
Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / is_all_day / default
```
Removed value: -null
```
- removedInput schema / properties / is_all_day / title
```
Removed value: -"Is All Day"
```
- addedInput schema / properties / is_all_day / type
```
Added value: +"boolean"
```
- removedInput schema / properties / key / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / key / default
```
Removed value: -null
```
- removedInput schema / properties / key / title
```
Removed value: -"Key"
```
- addedInput schema / properties / key / type
```
Added value: +"string"
```
- removedInput schema / properties / location / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / location / default
```
Removed value: -null
```
- removedInput schema / properties / location / title
```
Removed value: -"Location"
```
- addedInput schema / properties / location / type
```
Added value: +"string"
```
- changedInput schema / properties / recurrence / anyOf
```
Previous value: -[
-  {
-    "additionalProperties": true,
-    "type": "object"
-  },
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "type": "object"
+  },
+  {
+    "type": "string"
+  }
+]
```
- removedInput schema / properties / recurrence / default
```
Removed value: -null
```
- removedInput schema / properties / recurrence / title
```
Removed value: -"Recurrence"
```
- removedInput schema / properties / remove_recurrence / title
```
Removed value: -"Remove Recurrence"
```
- removedInput schema / properties / show_as / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / show_as / default
```
Removed value: -null
```
- removedInput schema / properties / show_as / title
```
Removed value: -"Show As"
```
- addedInput schema / properties / show_as / type
```
Added value: +"string"
```
- removedInput schema / properties / start / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / start / default
```
Removed value: -null
```
- removedInput schema / properties / start / title
```
Removed value: -"Start"
```
- addedInput schema / properties / start / type
```
Added value: +"string"
```
- removedInput schema / properties / subject / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / subject / default
```
Removed value: -null
```
- removedInput schema / properties / subject / title
```
Removed value: -"Subject"
```
- addedInput schema / properties / subject / type
```
Added value: +"string"
```
- removedInput schema / properties / timezone / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- removedInput schema / properties / timezone / default
```
Removed value: -null
```
- removedInput schema / properties / timezone / title
```
Removed value: -"Timezone"
```
- addedInput schema / properties / timezone / type
```
Added value: +"string"
```
- removedInput schema / title
```
Removed value: -"outlook_update_eventArguments"
```

Changed1 schema field changedv1.28.0Oct 25, 2026

addedInput schema / properties / key

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Key"
+}

Changed1 schema field changedv1.23.0Oct 1, 2026

addedInput schema / properties / timezone

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Timezone"
+}

Changed1 schema field changedv1.22.1Sep 30, 2026

addedInput schema / properties / show_as

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Show As"
+}

Changed4 schema fields changedv1.19.0Sep 9, 2026

addedInput schema / properties / attendees

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

addedInput schema / properties / is_all_day

Added value: +{
+  "anyOf": [
+    {
+      "type": "boolean"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Is All Day"
+}

addedInput schema / properties / recurrence

Added value: +{
+  "anyOf": [
+    {
+      "additionalProperties": true,
+      "type": "object"
+    },
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Recurrence"
+}

addedInput schema / properties / remove_recurrence

Added value: +{
+  "default": false,
+  "title": "Remove Recurrence",
+  "type": "boolean"
+}

First observedv1.11.0Jun 10, 2026

TDQS

A4.6/5.0

Behavior5/5

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

With only destructiveHint=true to rely on, the description discloses real side effects: attendees sends invitations and cancellations, [] removes everyone, recurrence edits convert single↔series, and series patches are refused when occurrences were edited or deleted. It also explains that False and [] are instructions rather than absences — exactly the semantic an agent would otherwise get wrong.

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?

Front-loaded with the core patch semantic, then organized by parameter in a scannable way. It is long and dense, but nearly every sentence carries a non-obvious constraint; minor redundancy around the mutual-exclusivity of recurrence and remove_recurrence.

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?

For a 13-parameter destructive mutation with no output schema and 0% schema coverage, the description covers the semantics an agent needs to call it safely, including failure conditions (series with edited occurrences) and side effects (invitations, cancellations). Nothing critical is left implicit.

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

Parameters4/5

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

Schema coverage is 0%, so the description must carry the load, and it does for the tricky parameters: recurrence shapes, attendees replacement and invitation side effects, is_all_day's midnight/same-call constraint, timezone re-anchoring, and that show_as and key patch standalone. It adds no detail for subject, body, location, or event_id, but those are self-evident.

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 and resource ('Update fields on an existing event') and immediately qualifies the semantics with 'partial patch — only provided fields change'. This clearly separates it from outlook_create_event and outlook_delete_event without needing to open 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 Guidelines4/5

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

Gives strong conditional guidance throughout: omit recurrence to leave it alone, pass remove_recurrence=True to break a series, attendees replaces the whole list, is_all_day requires start/end. It stops short of naming sibling alternatives explicitly (e.g. 'use outlook_create_event for new events'), so it is context-rich but not a full when/when-not/alternatives map.

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

Deploy Server

outlook_update_event

Instructions

Input Schema

Schema Changelog

TDQS

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