Microsoft 365 MCP Server

tentatively-accept-calendar-event

tentatively-accept-calendar-event

Destructive

Tentatively accept a Microsoft 365 calendar event to signal possible attendance, and optionally propose a new meeting time when the invite allows alternatives.

Instructions

Tentatively accept the specified event in a user calendar. If the event allows proposals for new times, on responding tentative to the event, an invitee can choose to suggest an alternative time by including the proposedNewTime parameter. For more information on how to propose a time, and how to receive and accept a new time proposal, see Propose new meeting times.

💡 TIP: Tentatively accepts a meeting invitation. Optional body: { sendResponse: true, comment: 'I might be able to attend.' }. Use proposedNewTime to suggest an alternative: { proposedNewTime: { start: { dateTime, timeZone }, end: { dateTime, timeZone } } }.

Input Schema

TableJSON Schema

Name	Required	Description
`body`	Yes
`confirm`	No	For destructive operations when the confirm gate is enabled (MS365_MCP_REQUIRE_CONFIRM=true; off by default). Set to true only after the user has explicitly approved this action. When the gate is on, calls without confirm: true return { error: "confirmation_required" } without touching user data.
`eventId`	Yes	Value for the 'eventId' path segment. Pass it under the name 'eventId', not as 'id'. Use the 'id' field of the event object as returned by Microsoft Graph.
`includeHeaders`	No	Include response headers (including ETag) in the response metadata
`excludeResponse`	No	Exclude the full response body and only return success or failure indication

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.145.2Aug 22, 2026

removedInput schema / $defs

Removed value: -{
-  "def0": {
-    "additionalProperties": true,
-    "properties": {
-      "dateTime": {
-        "description": "A single point of time in a combined date and time representation ({date}T{time}; for example, 2017-08-29T04:00:00.0000000).",
-        "type": "string"
-      },
-      "timeZone": {
-        "description": "Represents a time zone, for example, 'Pacific Standard Time'. See below for more possible values.",
-        "type": [
-          "string",
-          "null"
-        ]
-      }
-    },
-    "type": "object"
-  }
-}

changedInput schema / properties / body / properties / ProposedNewTime / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "properties": {
-      "end": {
-        "$ref": "#/$defs/def0"
-      },
-      "start": {
-        "$ref": "#/$defs/def0"
-      }
-    },
-    "type": "object"
-  },
-  {
-    "additionalProperties": true,
-    "properties": {},
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "properties": {
+      "end": {
+        "additionalProperties": true,
+        "properties": {
+          "dateTime": {
+            "description": "A single point of time in a combined date and time representation ({date}T{time}; for example, 2017-08-29T04:00:00.0000000).",
+            "type": "string"
+          },
+          "timeZone": {
+            "description": "Represents a time zone, for example, 'Pacific Standard Time'. See below for more possible values.",
+            "type": [
+              "string",
+              "null"
+            ]
+          }
+        },
+        "type": "object"
+      },
+      "start": {
+        "additionalProperties": true,
+        "properties": {
+          "dateTime": {
+            "description": "A single point of time in a combined date and time representation ({date}T{time}; for example, 2017-08-29T04:00:00.0000000).",
+            "type": "string"
+          },
+          "timeZone": {
+            "description": "Represents a time zone, for example, 'Pacific Standard Time'. See below for more possible values.",
+            "type": [
+              "string",
+              "null"
+            ]
+          }
+        },
+        "type": "object"
+      }
+    },
+    "type": "object"
+  },
+  {
+    "additionalProperties": true,
+    "properties": {},
+    "type": "object"
+  }
+]

Changed3 schema fields changedv0.134.4Jul 28, 2026

addedInput schema / $defs

Added value: +{
+  "def0": {
+    "additionalProperties": true,
+    "properties": {
+      "dateTime": {
+        "description": "A single point of time in a combined date and time representation ({date}T{time}; for example, 2017-08-29T04:00:00.0000000).",
+        "type": "string"
+      },
+      "timeZone": {
+        "description": "Represents a time zone, for example, 'Pacific Standard Time'. See below for more possible values.",
+        "type": [
+          "string",
+          "null"
+        ]
+      }
+    },
+    "type": "object"
+  }
+}

changedInput schema / properties / body / properties / ProposedNewTime / anyOf

Previous value: -[
-  {
-    "additionalProperties": true,
-    "properties": {
-      "end": {
-        "additionalProperties": true,
-        "properties": {
-          "dateTime": {
-            "description": "A single point of time in a combined date and time representation ({date}T{time}; for example, 2017-08-29T04:00:00.0000000).",
-            "type": "string"
-          },
-          "timeZone": {
-            "description": "Represents a time zone, for example, 'Pacific Standard Time'. See below for more possible values.",
-            "type": [
-              "string",
-              "null"
-            ]
-          }
-        },
-        "type": "object"
-      },
-      "start": {
-        "$ref": "#/properties/body/properties/ProposedNewTime/anyOf/0/properties/end"
-      }
-    },
-    "type": "object"
-  },
-  {
-    "additionalProperties": true,
-    "properties": {},
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": true,
+    "properties": {
+      "end": {
+        "$ref": "#/$defs/def0"
+      },
+      "start": {
+        "$ref": "#/$defs/def0"
+      }
+    },
+    "type": "object"
+  },
+  {
+    "additionalProperties": true,
+    "properties": {},
+    "type": "object"
+  }
+]

changedInput schema / properties / eventId / description

Previous value: -"Path parameter: eventId"New value: +"Value for the 'eventId' path segment. Pass it under the name 'eventId', not as 'id'. Use the 'id' field of the event object as returned by Microsoft Graph."

Addedv0.131.2Jul 18, 2026
Removedv0.131.2Jul 18, 2026

Changed1 schema field changedv0.131.1Jul 11, 2026

addedInput schema / properties / confirm

Added value: +{
+  "description": "For destructive operations when the confirm gate is enabled (MS365_MCP_REQUIRE_CONFIRM=true; off by default). Set to true only after the user has explicitly approved this action. When the gate is on, calls without confirm: true return { error: \"confirmation_required\" } without touching user data.",
+  "type": "boolean"
+}

Addedv0.114.0May 28, 2026
Removedv0.112.2May 22, 2026
Addedv0.110.0May 18, 2026
Removedv0.108.0May 15, 2026
Addedv0.96.0May 4, 2026

TDQS

A4.1/5.0

Behavior3/5

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

Annotations declare `destructiveHint: true` and `readOnlyHint: false`, indicating this is a write operation. The description adds useful context: the optional body parameters (`sendResponse`, `comment`), the conditional ability to propose a new time, and an example. However, it does not disclose whether the action is reversible, what the event status becomes, or any side effects beyond sending a response. Since annotations already cover the mutation nature, the description adds some value but remains thin on deeper behavioral consequences.

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 verbose, with a main explanatory paragraph and a 'TIP' section containing examples. Each sentence adds actionable information: the core action, the proposal condition, and concrete usage examples. It is more than two sentences but not bloated; the structure is logical with the tip reinforcing the main text. Some redundancy exists (e.g., the phrase 'Tentatively accepts a meeting invitation' echoes the first line), but overall it is efficiently organized.

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?

The tool has nested objects, optional proposals, a confirm gate, and multiple parameters. The description covers the primary purpose, the optional new-time feature, and provides examples for the most complex part (body). It also flags the confirm gate requirement. It does not describe the response format (no output schema) or specify error conditions (e.g., if the event doesn't allow proposals), but given the absence of an output schema and the moderate complexity, the description provides enough context for an agent to invoke it correctly. A reference to external docs fills the gap for edge cases.

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 80%, so many parameters already have descriptions. The description adds significant value beyond the schema: it provides concrete JSON examples for the optional body and proposedNewTime, clarifies that `eventId` must be passed as 'eventId' not 'id', and explains the `confirm` gate. It also disambiguates the nested `proposedNewTime` structure. This extra guidance compensates for the 20% undocumented parameters (like `includeHeaders` and `excludeResponse` are self-explanatory but not covered).

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 clearly states the action: 'Tentatively accept the specified event in a user calendar.' It names the verb, resource (calendar event), and the specific state change (tentative acceptance). It indirectly distinguishes from siblings like `accept-calendar-event` and `decline-calendar-event` by its name and action, and the mention of proposing alternative times adds unique purpose. This is a specific, unambiguous verb+resource combination.

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?

The description explains when this tool is appropriate: 'Tentatively accepts a meeting invitation' and describes the optional new-time proposal behavior. It references external documentation for proposing times, but does not explicitly state when to use alternatives like `accept-calendar-event` or `decline-calendar-event`. The context is clear but exclusions against siblings are not spelled out, so it falls short of a perfect score.

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

Deploy Server

tentatively-accept-calendar-event

Instructions

Input Schema

Schema Changelog

TDQS

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