TimeTree MCP Server

update_event

DestructiveIdempotent

Modify an existing TimeTree event by sending only the fields to change and receive the updated event; array fields replace current values, and recurring events update every occurrence.

Instructions

Change an event and return the updated event. Only provide the fields to change; array fields (attendees, alerts, recurrences, checklist, virtual attendees) replace the current values. For a recurring event this changes every occurrence; to change one occurrence or the ones after it, use update_event_occurrence. For memos use update_memo.

Input Schema

TableJSON Schema

Name	Required	Description
`url`	No	New related URL; use an empty string to remove it
`note`	No	New event notes
`title`	No	New event title
`alerts`	No	Replace notification offsets in minutes; use [] to clear
`end_at`	No	New end time as Unix timestamp in milliseconds
`all_day`	No	Whether this is an all-day event
`category`	No	New event category
`label_id`	No	Color label ID (1-10): 1=Emerald green, 2=Modern cyan, 3=Deep sky blue, 4=Pastel brown, 5=Midnight black, 6=Apple red, 7=French rose, 8=Coral pink, 9=Bright orange, 10=Soft violet
`location`	No	New event location
`start_at`	No	New start time as Unix timestamp in milliseconds
`attendees`	No	Replace calendar user attendee IDs
`checklist`	No	Replace event checklist items. Use [] to clear checklist.
`event_uuid`	Yes	The UUID of the event to update (from get_events)
`file_uuids`	No	Replace attached file UUIDs
`calendar_id`	Yes	The calendar ID from list_calendars (numeric string; numbers are also accepted)
`recurrences`	No	Replace recurrence RRULE strings
`end_timezone`	No	New end timezone
`start_timezone`	No	New start timezone (e.g., "Asia/Seoul")
`virtual_user_attendees`	No	Replace virtual member attendees. Use [] to clear.

Output Schema

TableJSON Schema

Name	Required	Description	Default
`event`	Yes
`message`	No
`success`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.7.0Oct 22, 2026

changedInput schema / properties / label_id / description

Previous value: -"New color label ID (1-10)"New value: +"Color label ID (1-10): 1=Emerald green, 2=Modern cyan, 3=Deep sky blue, 4=Pastel brown, 5=Midnight black, 6=Apple red, 7=French rose, 8=Coral pink, 9=Bright orange, 10=Soft violet"

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "event": {
+      "properties": {
+        "alerts": {
+          "type": "array"
+        },
+        "all_day": {
+          "type": "boolean"
+        },
+        "attendees": {
+          "items": {
+            "type": "number"
+          },
+          "type": "array"
+        },
+        "calendar_id": {
+          "type": "number"
+        },
+        "category": {
+          "description": "1 = event, 2 = memo",
+          "type": [
+            "number",
+            "null"
+          ]
+        },
+        "checklist": {
+          "type": [
+            "array",
+            "null"
+          ]
+        },
+        "created_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "end_at": {
+          "description": "ISO 8601 date-time (UTC)",
+          "type": "string"
+        },
+        "end_timezone": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "label_color": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "label_id": {
+          "type": [
+            "number",
+            "null"
+          ]
+        },
+        "location": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "note": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "parent_id": {
+          "description": "Series uuid when this event is an edited occurrence",
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "recurrences": {
+          "items": {
+            "type": "string"
+          },
+          "type": "array"
+        },
+        "start_at": {
+          "description": "ISO 8601 date-time (UTC)",
+          "type": "string"
+        },
+        "start_timezone": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "title": {
+          "type": "string"
+        },
+        "updated_at": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "url": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "uuid": {
+          "type": "string"
+        },
+        "virtual_user_attendees": {
+          "type": "array"
+        }
+      },
+      "required": [
+        "uuid",
+        "title",
+        "start_at",
+        "end_at",
+        "all_day"
+      ],
+      "type": "object"
+    },
+    "message": {
+      "type": "string"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success",
+    "event"
+  ],
+  "type": "object"
+}

Changed3 schema fields changedv0.4.0Oct 3, 2026

changedInput schema / properties / calendar_id / description

Previous value: -"The calendar ID"New value: +"The calendar ID from list_calendars (numeric string; numbers are also accepted)"

changedInput schema / properties / calendar_id / type
```
Previous value: -"number"New value: +"string"
```

changedInput schema / properties / url / description

Previous value: -"New related URL"New value: +"New related URL; use an empty string to remove it"

First observedv0.3.0May 27, 2026

TDQS

A4.7/5.0

Behavior4/5

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

Annotations already flag destructiveHint=true and idempotentHint=true, but the description adds genuinely new behavioral context: array fields overwrite rather than append, and a recurring event edit applies to every occurrence. It stops short of permissions/auth or rate-limit context, so 4 rather than 5.

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?

Three tight sentences: action first, mutation semantics second, sibling routing last. Zero filler, and the most decision-relevant content is front-loaded.

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?

An output schema exists so return values need no prose, and 19 parameters are fully described in the schema. The description covers the remaining risk areas an agent needs — PATCH-style omission, array replacement, and recurrence scope — making it complete for a destructive mutation tool.

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 100%, so per-field meaning is already documented; the description's value-add is the cross-cutting semantics that the schema cannot express — omit fields to leave them unchanged, supply arrays to replace wholesale, pass empty arrays to clear. That is meaningful beyond the schema, though it doesn't address the timestamps/timezone pairing specifically.

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?

"Change an event and return the updated event" gives a specific verb plus resource and states the return contract. It also explicitly distinguishes itself from update_event_occurrence and update_memo, so an agent can pick the right tool without opening schemas.

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?

It states the partial-update rule ("Only provide the fields to change"), the replacement rule for array fields, and names two alternatives with the exact conditions that select them (single-occurrence edits, memos). Nothing about when to use this vs. siblings is left to inference.

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