What can you do with this server?

This server lets you manage iCloud Calendar events over MCP, with discovery, reading, creation, updating, and deletion of calendar data. * List all calendars available to the configured iCloud account. * List and paginate events in a semi-open time range up to 366 days, with recurring occurrences expanded. * Get a single event by opaque resource ID or by calendar ID + UID, optionally including raw iCalendar. * Create timed, all-day, and recurring events with zero or more DISPLAY alarms. * Update events or complete recurring series using partial patches that preserve omitted fields. * Delete an event or complete recurring series, optionally guarded by an expected ETag. * Use ETags for optimistic concurrency, support multiple alarms per event, and avoid isolated recurrence mutations.

Which integrations are available for this server?

Allows managing iCloud Calendar events, including creating, updating, deleting, and listing events with support for alarms and recurrence.

How do I use CalDAV MCP Server?

1. Click on "Install Server". 2. Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state. 3. In the chat, type @ followed by the MCP server name and your instructions, e.g., "@CalDAV MCP Server list events from my work calendar for next Monday" That's it! The server will respond to your query, and you can continue using it as needed. Here is a step-by-step guide with screenshots.

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CalDAV MCP Server

by lukegskw

Overview Schema Related Servers Score Discussions(2)

TypeScript

Remote

CalDAV MCP Server

TypeScript npm npm downloads Container MCP Registry License

CalDAV MCP Server is a Model Context Protocol server for managing iCloud Calendar events, including native support for multiple VALARM reminders on one event.

iCloud Calendar is the only provider officially supported and manually validated in the first release. The server works with any MCP client that supports stdio or Streamable HTTP.

This independent project is not affiliated with, authorized, sponsored, or approved by Apple Inc. Apple and iCloud are trademarks of their respective owner.

Quick start

Install Node.js 24+, create an Apple app-specific password, and add this local stdio server to a JSON-configured MCP client such as Claude Desktop or Gemini:

{
  "mcpServers": {
    "icloud-calendar": {
      "command": "npx",
      "args": ["--yes", "@lukegskw/caldav-mcp@latest"],
      "env": {
        "CALDAV_USERNAME": "user@example.com",
        "CALDAV_PASSWORD": "xxxx-xxxx-xxxx-xxxx"
      }
    }
  }
}

Restart the client and confirm that it lists six calendar tools. See client-specific setup and Docker deployment below. Keep the configuration file private because it contains the app-specific password.

Related MCP server: DAV MCP Server

About

The server connects one configured account to iCloud through CalDAV. It discovers the account's calendars and exposes normalized read and write operations through MCP.

Updates preserve the complete iCalendar resource, including unknown properties, Apple extensions, VTIMEZONE, recurrence exceptions, and alarms omitted from a patch. Writes use opaque resource identifiers and ETags instead of assuming that a CalDAV filename matches an event UID.

Calendar resources are processed in memory. The server has no telemetry and no application database, and raw iCalendar is returned only when explicitly requested.

Features

Discovers calendars available to the configured iCloud account.
Lists events in semi-open time ranges and expands recurring occurrences.
Creates timed, all-day, and recurring events.
Supports zero, one, or multiple display alarms per event.
Emits the Apple alarm extensions expected by iCloud Calendar.
Reads events by opaque resource ID or by calendar ID and UID.
Applies partial updates while preserving omitted and unknown iCalendar data.
Uses ETags for optimistic concurrency on updates and deletions.
Rejects isolated recurrence mutations instead of changing the complete series.
Redacts credentials, raw calendar content, and CalDAV paths from logs and errors.
Runs as a non-root container with a read-only root filesystem configuration.
Supports stdio and Streamable HTTP MCP transports.

MCP tools

`list_calendars`

Lists the calendars discovered for the configured account. Each result includes an opaque calendar_id, display name, description, timezone, and best-effort write status.

`list_events`

Lists events in a semi-open interval and expands recurring occurrences. The maximum range is 366 days, the default page size is 100, and the maximum page size is 500. Results use a deterministic chronological order. Pagination cursors are opaque and do not represent a snapshot when events are modified during traversal.

Example input:

{
  "calendar_id": "opaque-calendar-id",
  "start": "2026-09-01T00:00:00Z",
  "end": "2026-10-01T00:00:00Z",
  "timezone": "Europe/Berlin",
  "limit": 100
}

`get_event`

Reads an event by resource_id, or by a calendar_id and UID pair. Raw iCalendar is excluded by default and can be requested with include_raw_ical: true for controlled diagnostics.

`create_event`

Creates an event and reads back the representation stored by the server.

Timed event with two alarms:

{
  "calendar_id": "opaque-calendar-id",
  "summary": "Buy Shinkansen tickets",
  "start": {
    "date_time": "2026-09-06T03:00:00+02:00",
    "timezone": "Europe/Berlin"
  },
  "end": {
    "date_time": "2026-09-06T03:30:00+02:00",
    "timezone": "Europe/Berlin"
  },
  "description": "Smart-EX",
  "location": null,
  "alarms": [
    { "minutes_before": 1440, "action": "DISPLAY" },
    { "minutes_before": 0, "action": "DISPLAY" }
  ],
  "rrule": null
}

All-day event with an exclusive end date:

{
  "calendar_id": "opaque-calendar-id",
  "summary": "Trip",
  "start": { "date": "2026-09-06" },
  "end": { "date": "2026-09-08" },
  "alarms": []
}

Recurring events accept an RFC 5545 rule without the RRULE: prefix:

{
  "calendar_id": "opaque-calendar-id",
  "summary": "Weekly planning",
  "start": {
    "date_time": "2026-09-07T09:00:00+02:00",
    "timezone": "Europe/Berlin"
  },
  "end": {
    "date_time": "2026-09-07T09:30:00+02:00",
    "timezone": "Europe/Berlin"
  },
  "rrule": "FREQ=WEEKLY;BYDAY=MO;COUNT=10"
}

`update_event`

Patches an event or complete recurring series. Omitted fields are preserved, null removes a nullable field, and alarms: [] removes all alarms. An optional expected_etag prevents overwriting a newer server version.

`delete_event`

Deletes an event or complete recurring series, optionally requiring an observed ETag. Deleting a single expanded occurrence is not supported in the current release.

Tech stack

Installation

Prerequisites

An iCloud account with Calendar enabled.
Two-factor authentication enabled for the Apple Account.
An app-specific password.
Docker and Docker Compose for container deployment, or Node.js 24+ for npx.
pnpm is required only when building from source. Corepack and CI use the version pinned in package.json.

npm / npx

No global install or repository clone is required. MCP clients can launch the latest published package directly:

CALDAV_USERNAME='user@example.com' \
CALDAV_PASSWORD='xxxx-xxxx-xxxx-xxxx' \
npx --yes @lukegskw/caldav-mcp@latest

The command waits for MCP messages on stdin and normally prints nothing to stdout. In practice, add it to the client configuration as shown in MCP client setup. For reproducible environments, replace latest with an exact published version such as X.Y.Z.

Docker Compose

The recommended installation uses the published multi-architecture image:

ghcr.io/lukegskw/caldav-mcp:latest

Download the Compose example:

curl -O https://raw.githubusercontent.com/lukegskw/caldav-mcp/main/compose.example.yaml

Provide the Apple Account email and app-specific password, then start the service:

export CALDAV_USERNAME='user@example.com'
export CALDAV_PASSWORD='xxxx-xxxx-xxxx-xxxx'
docker compose -f compose.example.yaml up -d

To publish a different host port, set:

export CALDAV_MCP_PUBLISHED_PORT=18100
docker compose -f compose.example.yaml up -d

The latest tag follows the newest stable release. Stable releases also publish an exact tag such as 0.1.6 and a minor-series tag such as 0.1. The Compose example pins latest by digest so deployments are reproducible. To upgrade, download the updated Compose example or replace the full image reference with the desired published version and digest.

The Streamable HTTP endpoint will be available at:

http://<host>:8100/mcp

The host port can change without changing port 8100 inside the container. No persistent volume is required; calendar data remains in iCloud.

Docker run

The same hardened container configuration can be started directly:

docker run -d \
  --name caldav-mcp \
  --restart unless-stopped \
  --read-only \
  --user 10001:10001 \
  --cap-drop ALL \
  --security-opt no-new-privileges:true \
  --tmpfs /tmp:size=16m,mode=1777 \
  -e CALDAV_PROVIDER=icloud \
  -e CALDAV_USERNAME \
  -e CALDAV_PASSWORD \
  -e CALDAV_MCP_TRANSPORT=streamable-http \
  -e CALDAV_MCP_HOST=0.0.0.0 \
  -p 8100:8100 \
  ghcr.io/lukegskw/caldav-mcp:latest

Build the container from source

Building locally is optional. Prefer the published image unless you need to modify or audit the container build.

git clone https://github.com/lukegskw/caldav-mcp.git
cd caldav-mcp
docker buildx build --load -t caldav-mcp:local .

Local Node.js installation

Builds and typechecks use TypeScript 7. The typescript dependency aliases @typescript/typescript6 for ESLint, which still requires the TypeScript 6 API; @typescript/native supplies TypeScript 7’s tsc executable. See the TypeScript migration guidance.

git clone https://github.com/lukegskw/caldav-mcp.git
cd caldav-mcp
pnpm install --frozen-lockfile
cp .env.example .env
pnpm build
pnpm start -- --transport stdio

In stdio mode, stdout is reserved exclusively for MCP messages. To run Streamable HTTP locally:

CALDAV_MCP_TRANSPORT=streamable-http pnpm start

Configuration

All settings use the CALDAV_ or CALDAV_MCP_ prefix.

Variable	Required	Default	Description
`CALDAV_PROVIDER`	No	`icloud`	Provider policy. iCloud is the supported profile.
`CALDAV_URL`	No	`https://caldav.icloud.com`	CalDAV discovery URL.
`CALDAV_USERNAME`	Yes	None	Apple Account email.
`CALDAV_PASSWORD`	Yes	None	App-specific password, not the account password.
`CALDAV_MCP_TRANSPORT`	No	`stdio`	`stdio` or `streamable-http`.
`CALDAV_MCP_HOST`	No	`0.0.0.0`	HTTP bind address.
`CALDAV_MCP_PORT`	No	`8100`	HTTP listening port.
`CALDAV_MCP_LOG_LEVEL`	No	`INFO`	Application log level.
`CALDAV_MCP_REQUEST_TIMEOUT_MS`	No	`30000`	CalDAV request timeout.

The core retains an experimental generic provider policy and configurable URL to keep Apple extensions isolated from the shared iCalendar implementation. No compatibility with other providers is currently claimed.

Secrets must be supplied through the deployment platform or environment. Never commit .env, pass credentials as MCP tool arguments, or include them in diagnostic reports.

MCP client setup

Gemini CLI extension

Install directly from GitHub and enable automatic extension updates:

gemini extensions install https://github.com/lukegskw/caldav-mcp --auto-update

Gemini prompts for the username and stores the app-specific password as a sensitive setting. The public extension gallery discovers tagged releases from this repository.

Manual configuration

For any MCP client that accepts Streamable HTTP server definitions, configure the URL:

mcp_servers:
  caldav:
    url: http://<host>:8100/mcp

If the client shares the Compose network, use the service name and internal port:

mcp_servers:
  caldav:
    url: http://caldav-mcp:8100/mcp

For clients that launch local stdio servers, prefer the npm command from Quick start. If a desktop client cannot find npx, use the absolute path reported by command -v npx on macOS/Linux or where npx on Windows.

Claude Desktop

Add the Quick start JSON under mcpServers in claude_desktop_config.json, then completely restart Claude Desktop. Open the file through Settings -> Developer -> Edit Config instead of assuming its location.

Claude Code

Claude Code can add the same stdio server at user scope:

claude mcp add --transport stdio --scope user \
  --env CALDAV_USERNAME=user@example.com \
  --env CALDAV_PASSWORD=xxxx-xxxx-xxxx-xxxx \
  icloud-calendar -- npx --yes @lukegskw/caldav-mcp@latest

This command places the values in Claude's MCP configuration. Avoid running it where shell history is shared or retained insecurely.

Codex

Codex can add the server to its shared CLI and IDE configuration:

codex mcp add icloud-calendar \
  --env CALDAV_USERNAME=user@example.com \
  --env CALDAV_PASSWORD=xxxx-xxxx-xxxx-xxxx \
  -- npx --yes @lukegskw/caldav-mcp@latest

Run codex mcp list to verify it. For finer control, use the official Codex MCP configuration in ~/.codex/config.toml or a project-scoped .codex/config.toml.

Gemini CLI

Following the Gemini CLI MCP configuration, add the server under mcpServers in ~/.gemini/settings.json (user scope) or the project's .gemini/settings.json:

{
  "mcpServers": {
    "icloud-calendar": {
      "command": "npx",
      "args": ["--yes", "@lukegskw/caldav-mcp@latest"],
      "env": {
        "CALDAV_USERNAME": "user@example.com",
        "CALDAV_PASSWORD": "xxxx-xxxx-xxxx-xxxx"
      }
    }
  }
}

Claude Desktop (Docker, stdio alternative)

Claude Desktop launches local stdio servers as subprocesses. Running the published container this way keeps the app-specific password on the client machine and opens no network port, which matches the transport guidance in Limitations.

Add the server to claude_desktop_config.json:

{
  "mcpServers": {
    "icloud-calendar": {
      "command": "/absolute/path/to/docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "--env-file",
        "/absolute/path/to/caldav-mcp.env",
        "-e",
        "CALDAV_PROVIDER=icloud",
        "-e",
        "CALDAV_MCP_TRANSPORT=stdio",
        "ghcr.io/lukegskw/caldav-mcp@sha256:<digest>"
      ]
    }
  }
}

-i is required. Without an attached stdin the client cannot speak MCP to the container. --rm removes the container once the client stops it.

Supply credentials through --env-file rather than -e. Arguments passed to docker run are visible in the host process list; the contents of an env file are not. The file holds the variables described in Configuration:

CALDAV_USERNAME=user@example.com
CALDAV_PASSWORD=xxxx-xxxx-xxxx-xxxx

Pin the image by digest instead of latest, so that restarting the client cannot silently start a different version:

docker pull ghcr.io/lukegskw/caldav-mcp:latest
docker images --digests ghcr.io/lukegskw/caldav-mcp

Restart Claude Desktop completely after editing the configuration file.

Windows

When Claude Desktop is installed from the Microsoft Store, Windows redirects %APPDATA%\Claude into the package container and the file lives at:

%LOCALAPPDATA%\Packages\Claude_<package-id>\LocalCache\Roaming\Claude\claude_desktop_config.json

In that case dir %APPDATA%\Claude reports nothing. Server logs are written next to the configuration file, in logs\mcp-server-<server-name>.log.

Use the absolute path to docker.exe, because PATH inside the package container is not reliable. where docker prints it, typically C:\Program Files\Docker\Docker\resources\bin\docker.exe. Backslashes must be escaped in JSON.

Configuration formats differ between MCP clients. Consult the client's documentation for its exact schema and reload or restart it after changing the server definition.

Verification

Check the container state and logs:

docker compose -f compose.example.yaml ps
docker compose -f compose.example.yaml logs caldav-mcp

The container should report healthy. The TCP healthcheck validates the server process, not iCloud credentials.

Run the repository verification suite:

pnpm install --frozen-lockfile
pnpm format:check
pnpm lint
pnpm typecheck
pnpm test:unit
pnpm test:integration
pnpm build
pnpm test:package
pnpm test:distribution

Finally, connect with an MCP client and confirm that all six tools are listed. Before a release, run the dedicated iCloud manual validation against a test calendar.

Limitations

One iCloud account is configured per server process or container.
The Streamable HTTP endpoint has no authentication in the current release. Restrict it to a trusted LAN, VPN, or private container network; do not expose it directly to the internet.
Individual recurrence occurrences are read-only. Updating or deleting the complete series is supported.
Only ACTION:DISPLAY alarms are created.
Individual iCalendar resources are limited to 5 MiB.
Event list ranges are limited to 366 days and pages to 500 results.
Events may contain at most 20 alarms.
Attendee scheduling is outside the current scope.
Providers other than iCloud are not officially supported.

See troubleshooting for discovery, authentication, ETag, and Apple extension guidance. Review SECURITY.md before reporting a security issue or attaching diagnostics.

Contributing

Contributions are welcome. Before opening a pull request:

pnpm install --frozen-lockfile
pnpm format:check
pnpm lint
pnpm typecheck
pnpm test
pnpm build
docker buildx build --load -t caldav-mcp:test .

Changes to CalDAV writes or iCalendar serialization must preserve ETag checks, opaque resource boundaries, unknown properties, recurrence exceptions, and alarms omitted from patches. TypeScript changes must continue to satisfy the rules in .codex/rules/typescript.md.

Releasing

Releases are version-driven and automated from main so that a partial registry outage can be retried without publishing a second npm version.

Prepare the new version with pnpm release:prepare X.Y.Z. This synchronizes the npm, MCP Registry, and Gemini metadata.
Run the verification suite, including pnpm test:distribution.
Commit and push the release changes to main.
The release workflow validates the commit and creates the matching vX.Y.Z tag automatically before publishing.

The release workflow validates the versions, tests the packed npm artifact, and publishes the exact, minor-series, and latest container tags together with the npm package, MCP Registry entry, and GitHub release. Prereleases receive only their exact container tag. Gemini can discover the tagged extension without another per-release edit. A rerun skips matching artifacts that already exist and resumes the missing steps. See the container release strategy for the CI and tagging decisions.

License

MIT. See LICENSE.

Available Tools

6 tools

create_eventCreate calendar eventA

Create a new event in a writable iCloud calendar and return the stored representation; existing events are not changed. Use list_calendars first to obtain calendar_id, and use update_event when the event already exists. Timed values require matching offsets and timezones, all-day end dates are exclusive, and recurrence rules omit the RRULE: prefix.

ParametersJSON Schema

Name	Required	Description
`end`	Yes	Event end using the same temporal type and timezone as start; an all-day end date is exclusive.
`rrule`	No	RFC 5545 recurrence rule without the RRULE: prefix; defaults to null.
`start`	Yes	Event start as a timed date-time or all-day date.
`alarms`	No	Display reminders; defaults to an empty array.
`summary`	Yes	Event title, between 1 and 1,024 characters.
`location`	No	Event location; defaults to null.
`calendar_id`	Yes	Opaque destination calendar ID returned by list_calendars.
`description`	No	Event notes; defaults to null.

Output Schema

ParametersJSON Schema

Name	Required	Description
`end`	Yes	Normalized event end.
`uid`	Yes	Stored iCalendar UID.
`etag`	Yes	Current ETag for optimistic concurrency, when available.
`href`	Yes	Redacted fingerprint of the CalDAV resource URL.
`rrule`	Yes	Stored RFC 5545 recurrence rule without the RRULE: prefix.
`start`	Yes	Normalized event start.
`alarms`	Yes	Normalized alarms attached to the event.
`summary`	Yes	Stored event title.
`location`	Yes	Stored event location.
`raw_ical`	No	Raw iCalendar resource, included only when explicitly requested.
`recurring`	Yes	Whether this event belongs to a recurring series.
`calendar_id`	Yes	Opaque ID of the containing calendar.
`description`	Yes	Stored event notes.
`resource_id`	Yes	Opaque event ID accepted by get_event, update_event, and delete_event.
`recurrence_id`	Yes	Occurrence identifier for an expanded recurring event.
`recurrence_exception`	Yes	Whether this result is an overridden recurrence instance.

TDQS

A4.7/5.0

Behavior5/5

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

Beyond annotations, the description adds meaningful behavioral context: it requires a writable calendar, returns the stored representation, guarantees existing events are unchanged, and warns about timezone offset matching, exclusive all-day end dates, and RRULE prefix omission. These constraints are not deducible from the annotations (readOnlyHint=false, destructiveHint=false).

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 sentences with no filler. The core purpose is front-loaded, and each subsequent sentence adds distinct, high-value guidance: prerequisites, alternative tool, and tricky format constraints. Every sentence earns its place.

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 complex create tool with 8 parameters, the description covers prerequisites, alternatives, return behavior, and the most error-prone input constraints. Since an output schema exists, it appropriately does not need to describe return structure further.

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 100%, so the schema already documents all parameters in detail. The description reinforces key constraints like timezone matching, exclusive all-day ends, and RRULE prefix omission, but these largely restate what the schema properties already say, adding limited new 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?

The description uses a specific verb and resource—'Create a new event in a writable iCloud calendar'—and explicitly contrasts with update_event by noting 'existing events are not changed.' This clearly differentiates the tool from its siblings like list_events and get_event.

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 gives explicit when-to-use guidance: 'Use list_calendars first to obtain calendar_id, and use update_event when the event already exists.' This directly routes an agent to prerequisites and alternatives, leaving no ambiguity about the tool's appropriate context.

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

delete_eventDelete calendar eventA

DestructiveIdempotent

Permanently delete an event or entire recurring series; individual expanded occurrences are not supported. Target it by resource_id or by calendar_id with uid, and supply expected_etag when available to prevent deleting a concurrently changed event.

ParametersJSON Schema

Name	Required	Description
`uid`	No	iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable.
`calendar_id`	No	Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable.
`resource_id`	No	Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid.
`expected_etag`	No	ETag previously returned for the event. When supplied, deletion fails if the event changed since it was read.

Output Schema

ParametersJSON Schema

Name	Required	Description
`deleted`	Yes	Confirms that the resource was deleted.
`resource_id`	Yes	Opaque ID of the deleted event resource.

TDQS

A4.5/5.0

Behavior5/5

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

Annotations already mark destructiveHint=true and readOnlyHint=false, but the description adds important context beyond them: 'Permanently delete' emphasizes irreversibility, 'entire recurring series' expands the blast radius, and the expected_etag note explains concurrency behavior. No contradiction with annotations; the description makes the destructive semantics vivid and accurate.

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 carry all essential information with no filler: the action first, then scope, then targeting alternatives, then expected_etag usage. Every clause earns its place, and the most important constraints are 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?

The description covers the essential behavior, the full targeting mechanism, a concurrency safety mechanism, and a key unsupported edge case. An output schema is present, so return-value details need not be described, and the tool is simple enough that nothing critical is missing.

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 100%, and each parameter already has a detailed description, including the 'provide it together/alone' relationship between uid, calendar_id, and resource_id. The description essentially paraphrases the same targeting and etag guidance without adding substantial new meaning, so the baseline of 3 applies.

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 opens with the specific verb 'delete' and resource 'event or entire recurring series', clearly distinguishing this destructive operation from create/update siblings. It explicitly calls out a key behavioral nuance (expanded occurrences not supported) that makes the tool's scope unambiguous.

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?

It gives concrete targeting instructions: use resource_id, or calendar_id with uid, and optionally expected_etag to guard against concurrent changes. It also states the exclusion for individual expanded occurrences, but it doesn't explicitly compare against alternatives like update_event when modification is desired. This is clear context with minor missing explicit 'when-not-to-use' guidance.

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

get_eventGet calendar eventA

Read-onlyIdempotent

Read one event by resource_id, preferably from a previous result, or by the calendar_id and uid pair. Use list_events for range searches. Request raw iCalendar only for controlled diagnostics because it may contain sensitive calendar data.

ParametersJSON Schema

Name	Required	Description
`uid`	No	iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable.
`calendar_id`	No	Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable.
`resource_id`	No	Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid.
`include_raw_ical`	No	Include the raw iCalendar resource for controlled diagnostics; it may contain sensitive calendar data. Defaults to false.

Output Schema

ParametersJSON Schema

Name	Required	Description
`end`	Yes	Normalized event end.
`uid`	Yes	Stored iCalendar UID.
`etag`	Yes	Current ETag for optimistic concurrency, when available.
`href`	Yes	Redacted fingerprint of the CalDAV resource URL.
`rrule`	Yes	Stored RFC 5545 recurrence rule without the RRULE: prefix.
`start`	Yes	Normalized event start.
`alarms`	Yes	Normalized alarms attached to the event.
`summary`	Yes	Stored event title.
`location`	Yes	Stored event location.
`raw_ical`	No	Raw iCalendar resource, included only when explicitly requested.
`recurring`	Yes	Whether this event belongs to a recurring series.
`calendar_id`	Yes	Opaque ID of the containing calendar.
`description`	Yes	Stored event notes.
`resource_id`	Yes	Opaque event ID accepted by get_event, update_event, and delete_event.
`recurrence_id`	Yes	Occurrence identifier for an expanded recurring event.
`recurrence_exception`	Yes	Whether this result is an overridden recurrence instance.

TDQS

A4.4/5.0

Behavior4/5

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

The annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, so the safety profile is clear. The description adds valuable behavioral context beyond annotations by warning that raw iCalendar may contain sensitive data and should only be requested for controlled diagnostics, and by noting that resource_id should preferably come from a previous result.

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 three concise, front-loaded sentences with no fluff. Each sentence earns its place: the primary lookup method, the alternative, and the sensitive-data caveat.

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?

Given the annotations, rich schema, and output schema, the description covers the main operational concerns: how to identify the event, when to use list_events, and the sensitive nature of raw iCalendar. It could be slightly more explicit about the fact that at least one identifier must be provided since the schema lists no required parameters, but the 'by... or by...' phrasing implies this.

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 100%, and each parameter already has a detailed explanation in the schema. The description restates the resource_id-vs-calendar_id+uid relationship and the raw iCalendar caution, but does not add substantial new parameter-level meaning beyond what the schema already provides, so a baseline 3 is appropriate.

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 begins with the specific verb 'Read one event' and identifies the resource as a calendar event, clearly distinguishing this from sibling tools. It also names the alternative lookup paths (resource_id vs calendar_id+uid pair), making the tool's purpose unmistakable.

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?

The description explicitly says to use list_events for range searches, which is a direct routing instruction to an alternative sibling. It also advises using resource_id from a previous result preferentially and restricts raw iCalendar requests to controlled diagnostics, giving clear when-to-use guidance.

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

list_calendarsList calendarsA

Read-onlyIdempotent

List calendars available in the configured iCloud account. Use this first to obtain the opaque calendar_id required by list_events and create_event; writable is a best-effort capability indicator.

ParametersJSON Schema

Name	Required	Description	Default
No parameters

Output Schema

ParametersJSON Schema

Name	Required	Description
`calendars`	Yes	Calendars available to the configured account.

TDQS

A4.9/5.0

Behavior5/5

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

The annotations already establish read-only, idempotent, and non-destructive behavior, and the description adds meaningful context: the writable field is only a best-effort capability indicator, and calendar IDs are opaque. This helps the agent avoid over-trusting the writable flag and treating IDs as human-readable.

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 two concise sentences with no filler. It leads with the core function and then adds the most important usage detail, making it easy to scan and act on.

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?

Given that the tool takes no parameters, has a rich set of annotations, and has an output schema, the description covers all necessary context: what is being listed, the account scope, the purpose of the returned IDs, and the reliability of the writable indicator.

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?

The input schema has no parameters, so the baseline for this dimension is 4. The description does not need to explain any parameter semantics because there are none.

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 that this tool lists calendars in the configured iCloud account, using a specific verb and resource. It also distinguishes itself from the sibling event tools by explaining that it provides the calendar_id needed by list_events and create_event.

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 explicitly instructs the agent to use this tool first in order to obtain the opaque calendar_id required by event operations. This gives clear sequencing guidance and explains the purpose of the tool relative to its siblings.

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

list_eventsList calendar eventsA

Read-onlyIdempotent

List events that overlap the start-inclusive, end-exclusive interval and expand recurring series into occurrences, across at most 366 days. Use list_calendars first to obtain calendar_id and use get_event instead for one known event. Continue with next_cursor and unchanged query filters when more results are available.

ParametersJSON Schema

Name	Required	Description
`end`	Yes	Exclusive end of the event search interval; must be after start and no more than 366 days later.
`limit`	No	Maximum events to return in this page, from 1 to 500; defaults to 100.
`start`	Yes	Inclusive start of the event search interval as an ISO 8601 instant.
`cursor`	No	Opaque next_cursor from the preceding page. Reuse it with the same calendar, interval, and timezone.
`timezone`	No	Fallback IANA timezone used when an event lacks timezone metadata during recurrence expansion.
`calendar_id`	Yes	Opaque calendar ID returned by list_calendars.

Output Schema

ParametersJSON Schema

Name	Required	Description
`events`	Yes	Events in deterministic chronological order for this page.
`next_cursor`	Yes	Opaque cursor for the next page, or null when this is the last page.

TDQS

A4.9/5.0

Behavior5/5

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

Annotations already indicate read-only, idempotent, non-destructive behavior, and the description adds substantial behavioral context: interval inclusivity, recurring series expansion, the 366-day maximum, and pagination continuation. This goes well beyond the structured annotation data and discloses important operation semantics.

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 dense sentences cover core behavior, prerequisites, alternative selection, and pagination without repetition or filler. The most critical semantic details are front-loaded, and every clause carries operational value.

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 paginated list operation with six parameters and an output schema, the description covers the required workflow (list_calendars, get_event), recurrence behavior, interval constraints, and pagination instructions. The output schema handles return-value details, and annotations cover the safety profile, so nothing essential is missing from the description.

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 the baseline is 3. The description adds value on top by explaining that calendar_id comes from list_calendars, that cursor must be reused with unchanged query filters, and that interval boundaries are inclusive/exclusive. This helps agents understand how the parameters relate to workflow even though the schema already documents each field.

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 uses a specific verb and resource ('List events') and defines precise interval semantics ('start-inclusive, end-exclusive') plus recurrence expansion. It also differentiates from related tools by saying to use 'get_event instead for one known event' and to use 'list_calendars first'. An agent can clearly understand what this tool does and how it differs from siblings.

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?

The description gives explicit workflow guidance: call list_calendars first for calendar_id, use get_event for a single known event, and paginate with next_cursor using unchanged filters. This directly tells the agent when to use this tool versus alternatives and how to handle multi-page results.

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

update_eventUpdate calendar eventA

Destructive

Modify an existing event or entire recurring series; individual expanded occurrences are not supported. Target it by resource_id or by calendar_id with uid. Omitted patch fields are preserved, null clears nullable fields, an empty alarms array removes alarms, and expected_etag can prevent a stale write.

ParametersJSON Schema

Name	Required	Description
`uid`	No	iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable.
`patch`	Yes	Fields to replace. Omitted fields are preserved; null clears nullable values and an empty alarms array removes all alarms.
`calendar_id`	No	Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable.
`resource_id`	No	Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid.
`expected_etag`	No	ETag previously returned for the event. When supplied, the update fails if the event changed since it was read.

Output Schema

ParametersJSON Schema

Name	Required	Description
`end`	Yes	Normalized event end.
`uid`	Yes	Stored iCalendar UID.
`etag`	Yes	Current ETag for optimistic concurrency, when available.
`href`	Yes	Redacted fingerprint of the CalDAV resource URL.
`rrule`	Yes	Stored RFC 5545 recurrence rule without the RRULE: prefix.
`start`	Yes	Normalized event start.
`alarms`	Yes	Normalized alarms attached to the event.
`summary`	Yes	Stored event title.
`location`	Yes	Stored event location.
`raw_ical`	No	Raw iCalendar resource, included only when explicitly requested.
`recurring`	Yes	Whether this event belongs to a recurring series.
`calendar_id`	Yes	Opaque ID of the containing calendar.
`description`	Yes	Stored event notes.
`resource_id`	Yes	Opaque event ID accepted by get_event, update_event, and delete_event.
`recurrence_id`	Yes	Occurrence identifier for an expanded recurring event.
`recurrence_exception`	Yes	Whether this result is an overridden recurrence instance.

TDQS

A4.5/5.0

Behavior4/5

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

Annotations already declare destructiveHint=true and readOnlyHint=false, and the description adds valuable behavioral context: patch semantics ('Omitted patch fields are preserved'), null clearing, empty alarms array behavior, and expected_etag preventing stale writes. This goes beyond what annotations provide and helps an agent predict side effects.

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 two sentences with no filler. It front-loads the core action and limitations, then packs targeting and patch semantics into a dense but readable second sentence. Every clause adds useful information.

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?

Given the rich input schema, output schema, and annotations, this description covers the essential operational details: what can be modified, how to identify the target, how patches behave, and how to prevent stale writes. No critical calling context appears missing.

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 the baseline is 3. The description earns a 4 by adding cross-parameter semantics not obvious from individual field descriptions: preservation of omitted fields, null clearing, empty alarms removal, and the optimistic concurrency role of expected_etag.

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 verb and resource: 'Modify an existing event or entire recurring series.' It also adds a critical scope limitation ('individual expanded occurrences are not supported') and distinguishes the tool from create/delete/list siblings by focusing on modification of existing entities.

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?

It gives concrete targeting guidance ('by resource_id or by calendar_id with uid') and a clear exclusion ('individual expanded occurrences are not supported'). It does not explicitly name alternatives like create_event or delete_event, but the context is clear enough for an agent to know when this tool applies.

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

Tool Schema Changelog

Recent tool additions, removals, and schema changes observed during successful MCP inspections. Dates show when Glama detected each change.

5 tool updatesv0.1.7Sep 5, 2026

Changedcreate_event14 fields changed

removedOutput schema / properties / alarms / items / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / alarms / items / properties / uid / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / uid / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / etag / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / etag / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / location / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / location / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / recurrence_id / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / recurrence_id / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / rrule / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / rrule / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Changedget_event14 fields changed

removedOutput schema / properties / alarms / items / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / alarms / items / properties / uid / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / uid / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / etag / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / etag / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / location / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / location / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / recurrence_id / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / recurrence_id / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / rrule / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / rrule / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Changedlist_calendars6 fields changed
- removedOutput schema / properties / calendars / items / properties / description / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / calendars / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / calendars / items / properties / timezone / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / calendars / items / properties / timezone / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / calendars / items / properties / writable / anyOf
```
Removed value: -[
-  {
-    "type": "boolean"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / calendars / items / properties / writable / type
```
Added value: +[
+  "boolean",
+  "null"
+]
```

Changedlist_events18 fields changed

changedInput schema / properties / end / pattern

Previous value: -"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"New value: +"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"

changedInput schema / properties / start / pattern

Previous value: -"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d(?::[0-5]\\d(?:\\.\\d+)?)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"New value: +"^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))T(?:(?:[01]\\d|2[0-3]):[0-5]\\d:[0-5]\\d(?:\\.\\d+)?(?:Z|([+-](?:[01]\\d|2[0-3]):[0-5]\\d)))$"

removedOutput schema / properties / events / items / properties / alarms / items / properties / description / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```
removedOutput schema / properties / events / items / properties / alarms / items / properties / uid / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / uid / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / events / items / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / events / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / events / items / properties / etag / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / events / items / properties / etag / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / events / items / properties / location / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / events / items / properties / location / type
```
Added value: +[
+  "string",
+  "null"
+]
```
removedOutput schema / properties / events / items / properties / recurrence_id / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
addedOutput schema / properties / events / items / properties / recurrence_id / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / events / items / properties / rrule / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / events / items / properties / rrule / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / next_cursor / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / next_cursor / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Changedupdate_event14 fields changed

removedOutput schema / properties / alarms / items / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / alarms / items / properties / uid / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / alarms / items / properties / uid / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / description / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / etag / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / etag / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / location / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / location / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / recurrence_id / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / recurrence_id / type
```
Added value: +[
+  "string",
+  "null"
+]
```

removedOutput schema / properties / rrule / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

addedOutput schema / properties / rrule / type
```
Added value: +[
+  "string",
+  "null"
+]
```

6 tool updatesv0.1.1Sep 4, 2026

Changedcreate_event37 fields changed

addedInput schema / properties / alarms / description

Added value: +"Display reminders; defaults to an empty array."

addedInput schema / properties / alarms / items / description
```
Added value: +"A display reminder attached to an event."
```
addedInput schema / properties / alarms / items / properties / action / description
```
Added value: +"Alarm action; only DISPLAY is supported."
```
addedInput schema / properties / alarms / items / properties / description / description
```
Added value: +"Optional notification text for this alarm."
```
addedInput schema / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before the event start; use 0 for an alarm at start time."
```

addedInput schema / properties / calendar_id / description

Added value: +"Opaque destination calendar ID returned by list_calendars."

addedInput schema / properties / description / description
```
Added value: +"Event notes; defaults to null."
```

changedInput schema / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A timed calendar value with an explicit offset and IANA timezone.",
+    "properties": {
+      "date_time": {
+        "description": "ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone for the local event time; its offset must match date_time.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedInput schema / properties / end / description

Added value: +"Event end using the same temporal type and timezone as start; an all-day end date is exclusive."

addedInput schema / properties / location / description
```
Added value: +"Event location; defaults to null."
```

addedInput schema / properties / rrule / description

Added value: +"RFC 5545 recurrence rule without the RRULE: prefix; defaults to null."

changedInput schema / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A timed calendar value with an explicit offset and IANA timezone.",
+    "properties": {
+      "date_time": {
+        "description": "ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone for the local event time; its offset must match date_time.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedInput schema / properties / start / description

Added value: +"Event start as a timed date-time or all-day date."

addedInput schema / properties / summary / description

Added value: +"Event title, between 1 and 1,024 characters."

addedOutput schema / properties / alarms / description

Added value: +"Normalized alarms attached to the event."

addedOutput schema / properties / alarms / items / description

Added value: +"A normalized alarm returned by iCloud Calendar."

addedOutput schema / properties / alarms / items / properties / action / description
```
Added value: +"Stored iCalendar alarm action."
```
addedOutput schema / properties / alarms / items / properties / description / description
```
Added value: +"Stored alarm notification text, when available."
```
addedOutput schema / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before event start, when representable."
```
addedOutput schema / properties / alarms / items / properties / uid / description
```
Added value: +"Stored alarm UID, when available."
```
addedOutput schema / properties / calendar_id / description
```
Added value: +"Opaque ID of the containing calendar."
```
addedOutput schema / properties / description / description
```
Added value: +"Stored event notes."
```

changedOutput schema / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / end / description
```
Added value: +"Normalized event end."
```

addedOutput schema / properties / etag / description

Added value: +"Current ETag for optimistic concurrency, when available."

addedOutput schema / properties / href / description

Added value: +"Redacted fingerprint of the CalDAV resource URL."

addedOutput schema / properties / location / description
```
Added value: +"Stored event location."
```

addedOutput schema / properties / raw_ical / description

Added value: +"Raw iCalendar resource, included only when explicitly requested."

addedOutput schema / properties / recurrence_exception / description

Added value: +"Whether this result is an overridden recurrence instance."

addedOutput schema / properties / recurrence_id / description

Added value: +"Occurrence identifier for an expanded recurring event."

addedOutput schema / properties / recurring / description

Added value: +"Whether this event belongs to a recurring series."

addedOutput schema / properties / resource_id / description

Added value: +"Opaque event ID accepted by get_event, update_event, and delete_event."

addedOutput schema / properties / rrule / description

Added value: +"Stored RFC 5545 recurrence rule without the RRULE: prefix."

changedOutput schema / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / start / description
```
Added value: +"Normalized event start."
```
addedOutput schema / properties / summary / description
```
Added value: +"Stored event title."
```
addedOutput schema / properties / uid / description
```
Added value: +"Stored iCalendar UID."
```

Changeddelete_event6 fields changed

addedInput schema / properties / calendar_id / description

Added value: +"Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable."

addedInput schema / properties / expected_etag / description

Added value: +"ETag previously returned for the event. When supplied, deletion fails if the event changed since it was read."

addedInput schema / properties / resource_id / description

Added value: +"Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid."

addedInput schema / properties / uid / description

Added value: +"iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable."

addedOutput schema / properties / deleted / description

Added value: +"Confirms that the resource was deleted."

addedOutput schema / properties / resource_id / description

Added value: +"Opaque ID of the deleted event resource."

Changedget_event27 fields changed

addedInput schema / properties / calendar_id / description

Added value: +"Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable."

addedInput schema / properties / include_raw_ical / description

Added value: +"Include the raw iCalendar resource for controlled diagnostics; it may contain sensitive calendar data. Defaults to false."

addedInput schema / properties / resource_id / description

Added value: +"Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid."

addedInput schema / properties / uid / description

Added value: +"iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable."

addedOutput schema / properties / alarms / description

Added value: +"Normalized alarms attached to the event."

addedOutput schema / properties / alarms / items / description

Added value: +"A normalized alarm returned by iCloud Calendar."

addedOutput schema / properties / alarms / items / properties / action / description
```
Added value: +"Stored iCalendar alarm action."
```
addedOutput schema / properties / alarms / items / properties / description / description
```
Added value: +"Stored alarm notification text, when available."
```
addedOutput schema / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before event start, when representable."
```
addedOutput schema / properties / alarms / items / properties / uid / description
```
Added value: +"Stored alarm UID, when available."
```
addedOutput schema / properties / calendar_id / description
```
Added value: +"Opaque ID of the containing calendar."
```
addedOutput schema / properties / description / description
```
Added value: +"Stored event notes."
```

changedOutput schema / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / end / description
```
Added value: +"Normalized event end."
```

addedOutput schema / properties / etag / description

Added value: +"Current ETag for optimistic concurrency, when available."

addedOutput schema / properties / href / description

Added value: +"Redacted fingerprint of the CalDAV resource URL."

addedOutput schema / properties / location / description
```
Added value: +"Stored event location."
```

addedOutput schema / properties / raw_ical / description

Added value: +"Raw iCalendar resource, included only when explicitly requested."

addedOutput schema / properties / recurrence_exception / description

Added value: +"Whether this result is an overridden recurrence instance."

addedOutput schema / properties / recurrence_id / description

Added value: +"Occurrence identifier for an expanded recurring event."

addedOutput schema / properties / recurring / description

Added value: +"Whether this event belongs to a recurring series."

addedOutput schema / properties / resource_id / description

Added value: +"Opaque event ID accepted by get_event, update_event, and delete_event."

addedOutput schema / properties / rrule / description

Added value: +"Stored RFC 5545 recurrence rule without the RRULE: prefix."

changedOutput schema / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / start / description
```
Added value: +"Normalized event start."
```
addedOutput schema / properties / summary / description
```
Added value: +"Stored event title."
```
addedOutput schema / properties / uid / description
```
Added value: +"Stored iCalendar UID."
```

Changedlist_calendars6 fields changed
- addedOutput schema / properties / calendars / description
```
Added value: +"Calendars available to the configured account."
```
- addedOutput schema / properties / calendars / items / properties / calendar_id / description
```
Added value: +"Opaque calendar ID used by event tools."
```
- addedOutput schema / properties / calendars / items / properties / description / description
```
Added value: +"Calendar description."
```
- addedOutput schema / properties / calendars / items / properties / display_name / description
```
Added value: +"Calendar display name."
```
- addedOutput schema / properties / calendars / items / properties / timezone / description
```
Added value: +"Calendar timezone, when advertised by the server."
```
- addedOutput schema / properties / calendars / items / properties / writable / description
```
Added value: +"Best-effort writable status; null means unknown."
```

Changedlist_events31 fields changed

addedInput schema / properties / calendar_id / description

Added value: +"Opaque calendar ID returned by list_calendars."

addedInput schema / properties / cursor / description

Added value: +"Opaque next_cursor from the preceding page. Reuse it with the same calendar, interval, and timezone."

addedInput schema / properties / end / description

Added value: +"Exclusive end of the event search interval; must be after start and no more than 366 days later."

addedInput schema / properties / limit / description

Added value: +"Maximum events to return in this page, from 1 to 500; defaults to 100."

addedInput schema / properties / start / description

Added value: +"Inclusive start of the event search interval as an ISO 8601 instant."

addedInput schema / properties / timezone / description

Added value: +"Fallback IANA timezone used when an event lacks timezone metadata during recurrence expansion."

addedOutput schema / properties / events / description

Added value: +"Events in deterministic chronological order for this page."

addedOutput schema / properties / events / items / properties / alarms / description
```
Added value: +"Normalized alarms attached to the event."
```
addedOutput schema / properties / events / items / properties / alarms / items / description
```
Added value: +"A normalized alarm returned by iCloud Calendar."
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / action / description
```
Added value: +"Stored iCalendar alarm action."
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / description / description
```
Added value: +"Stored alarm notification text, when available."
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before event start, when representable."
```
addedOutput schema / properties / events / items / properties / alarms / items / properties / uid / description
```
Added value: +"Stored alarm UID, when available."
```
addedOutput schema / properties / events / items / properties / calendar_id / description
```
Added value: +"Opaque ID of the containing calendar."
```
addedOutput schema / properties / events / items / properties / description / description
```
Added value: +"Stored event notes."
```

changedOutput schema / properties / events / items / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / events / items / properties / end / description
```
Added value: +"Normalized event end."
```
addedOutput schema / properties / events / items / properties / etag / description
```
Added value: +"Current ETag for optimistic concurrency, when available."
```
addedOutput schema / properties / events / items / properties / href / description
```
Added value: +"Redacted fingerprint of the CalDAV resource URL."
```
addedOutput schema / properties / events / items / properties / location / description
```
Added value: +"Stored event location."
```
addedOutput schema / properties / events / items / properties / raw_ical / description
```
Added value: +"Raw iCalendar resource, included only when explicitly requested."
```
addedOutput schema / properties / events / items / properties / recurrence_exception / description
```
Added value: +"Whether this result is an overridden recurrence instance."
```
addedOutput schema / properties / events / items / properties / recurrence_id / description
```
Added value: +"Occurrence identifier for an expanded recurring event."
```
addedOutput schema / properties / events / items / properties / recurring / description
```
Added value: +"Whether this event belongs to a recurring series."
```

addedOutput schema / properties / events / items / properties / resource_id / description

Added value: +"Opaque event ID accepted by get_event, update_event, and delete_event."

addedOutput schema / properties / events / items / properties / rrule / description
```
Added value: +"Stored RFC 5545 recurrence rule without the RRULE: prefix."
```

changedOutput schema / properties / events / items / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / events / items / properties / start / description
```
Added value: +"Normalized event start."
```
addedOutput schema / properties / events / items / properties / summary / description
```
Added value: +"Stored event title."
```
addedOutput schema / properties / events / items / properties / uid / description
```
Added value: +"Stored iCalendar UID."
```

addedOutput schema / properties / next_cursor / description

Added value: +"Opaque cursor for the next page, or null when this is the last page."

Changedupdate_event41 fields changed

addedInput schema / properties / calendar_id / description

Added value: +"Opaque calendar ID returned by list_calendars. Provide it together with uid when resource_id is unavailable."

addedInput schema / properties / expected_etag / description

Added value: +"ETag previously returned for the event. When supplied, the update fails if the event changed since it was read."

addedInput schema / properties / patch / description

Added value: +"Fields to replace. Omitted fields are preserved; null clears nullable values and an empty alarms array removes all alarms."

addedInput schema / properties / patch / properties / alarms / description

Added value: +"Replacement alarm set; use an empty array to remove all alarms."

addedInput schema / properties / patch / properties / alarms / items / description
```
Added value: +"A display reminder attached to an event."
```
addedInput schema / properties / patch / properties / alarms / items / properties / action / description
```
Added value: +"Alarm action; only DISPLAY is supported."
```
addedInput schema / properties / patch / properties / alarms / items / properties / description / description
```
Added value: +"Optional notification text for this alarm."
```
addedInput schema / properties / patch / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before the event start; use 0 for an alarm at start time."
```
addedInput schema / properties / patch / properties / description / description
```
Added value: +"Replacement notes; use null to clear the description."
```

changedInput schema / properties / patch / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A timed calendar value with an explicit offset and IANA timezone.",
+    "properties": {
+      "date_time": {
+        "description": "ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone for the local event time; its offset must match date_time.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedInput schema / properties / patch / properties / end / description

Added value: +"Replacement end; provide together with start. An all-day end date is exclusive."

addedInput schema / properties / patch / properties / location / description
```
Added value: +"Replacement location; use null to clear it."
```

addedInput schema / properties / patch / properties / rrule / description

Added value: +"Replacement RFC 5545 recurrence rule without RRULE:, or null to make the event non-recurring."

changedInput schema / properties / patch / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A timed calendar value with an explicit offset and IANA timezone.",
+    "properties": {
+      "date_time": {
+        "description": "ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone for the local event time; its offset must match date_time.",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedInput schema / properties / patch / properties / start / description
```
Added value: +"Replacement start; provide together with end."
```
addedInput schema / properties / patch / properties / summary / description
```
Added value: +"Replacement event title."
```

addedInput schema / properties / resource_id / description

Added value: +"Opaque event resource ID returned by list_events or get_event. Provide it alone instead of calendar_id and uid."

addedInput schema / properties / uid / description

Added value: +"iCalendar UID of the event. Provide it together with calendar_id when resource_id is unavailable."

addedOutput schema / properties / alarms / description

Added value: +"Normalized alarms attached to the event."

addedOutput schema / properties / alarms / items / description

Added value: +"A normalized alarm returned by iCloud Calendar."

addedOutput schema / properties / alarms / items / properties / action / description
```
Added value: +"Stored iCalendar alarm action."
```
addedOutput schema / properties / alarms / items / properties / description / description
```
Added value: +"Stored alarm notification text, when available."
```
addedOutput schema / properties / alarms / items / properties / minutes_before / description
```
Added value: +"Whole minutes before event start, when representable."
```
addedOutput schema / properties / alarms / items / properties / uid / description
```
Added value: +"Stored alarm UID, when available."
```
addedOutput schema / properties / calendar_id / description
```
Added value: +"Opaque ID of the containing calendar."
```
addedOutput schema / properties / description / description
```
Added value: +"Stored event notes."
```

changedOutput schema / properties / end / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / end / description
```
Added value: +"Normalized event end."
```

addedOutput schema / properties / etag / description

Added value: +"Current ETag for optimistic concurrency, when available."

addedOutput schema / properties / href / description

Added value: +"Redacted fingerprint of the CalDAV resource URL."

addedOutput schema / properties / location / description
```
Added value: +"Stored event location."
```

addedOutput schema / properties / raw_ical / description

Added value: +"Raw iCalendar resource, included only when explicitly requested."

addedOutput schema / properties / recurrence_exception / description

Added value: +"Whether this result is an overridden recurrence instance."

addedOutput schema / properties / recurrence_id / description

Added value: +"Occurrence identifier for an expanded recurring event."

addedOutput schema / properties / recurring / description

Added value: +"Whether this event belongs to a recurring series."

addedOutput schema / properties / resource_id / description

Added value: +"Opaque event ID accepted by get_event, update_event, and delete_event."

addedOutput schema / properties / rrule / description

Added value: +"Stored RFC 5545 recurrence rule without the RRULE: prefix."

changedOutput schema / properties / start / anyOf

Previous value: -[
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date_time": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
-        "type": "string"
-      },
-      "timezone": {
-        "maxLength": 4096,
-        "minLength": 1,
-        "type": "string"
-      }
-    },
-    "required": [
-      "date_time",
-      "timezone"
-    ],
-    "type": "object"
-  },
-  {
-    "additionalProperties": false,
-    "properties": {
-      "date": {
-        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
-        "type": "string"
-      }
-    },
-    "required": [
-      "date"
-    ],
-    "type": "object"
-  }
-]New value: +[
+  {
+    "additionalProperties": false,
+    "description": "A stored timed calendar value.",
+    "properties": {
+      "date_time": {
+        "description": "Stored ISO 8601 date-time with seconds and an explicit UTC offset or Z.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}(?:Z|[+-]\\d{2}:\\d{2})$",
+        "type": "string"
+      },
+      "timezone": {
+        "description": "IANA timezone associated with the stored date-time.",
+        "maxLength": 4096,
+        "minLength": 1,
+        "type": "string"
+      }
+    },
+    "required": [
+      "date_time",
+      "timezone"
+    ],
+    "type": "object"
+  },
+  {
+    "additionalProperties": false,
+    "description": "An all-day calendar value.",
+    "properties": {
+      "date": {
+        "description": "Calendar date in YYYY-MM-DD format.",
+        "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+        "type": "string"
+      }
+    },
+    "required": [
+      "date"
+    ],
+    "type": "object"
+  }
+]

addedOutput schema / properties / start / description
```
Added value: +"Normalized event start."
```
addedOutput schema / properties / summary / description
```
Added value: +"Stored event title."
```
addedOutput schema / properties / uid / description
```
Added value: +"Stored iCalendar UID."
```

6 tool updatesv0.1.0Sep 4, 2026
- First observedcreate_event
- First observeddelete_event
- First observedget_event
- First observedlist_calendars
- First observedlist_events
- First observedupdate_event

Install Server

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TDQS

A4.7/5.0

Disambiguation5/5

Each tool has a clear, distinct purpose: calendar discovery, range listing, single-event retrieval, create, update, and delete. get_event and list_events are explicitly differentiated as single-item lookup versus range search.

Naming Consistency5/5

All tool names follow a consistent verb_noun snake_case pattern, with appropriate pluralization for list operations. This makes the tool set predictable and easy to navigate.

Tool Count5/5

Six tools is well-scoped for a CalDAV server: calendar discovery plus full event CRUD. There is no bloat and no unnecessary overlap.

Completeness5/5

The tool set covers the full event lifecycle: list, get, create, update, and delete, with calendar discovery and handling for recurring series and ETags. No obvious gaps exist for typical calendar event workflows.

Maintenance

ActivityMaintained

ResponsivenessWithin a week

Resources

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CalDAV MCP Server

Quick start

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MCP tools

list_calendars

list_events

get_event

create_event

update_event

delete_event

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`list_calendars`

`list_events`

`get_event`

`create_event`

`update_event`

`delete_event`