icloud-mcp

calendar_find_free_time

Read-only

Find open slots of a required duration across iCloud calendars, with busy events and travel time accounted for. Ideal for proposing meeting times.

Instructions

Find open slots of at least duration_minutes within daily hours across the owner's calendars, with busy time and travel worked out for you.

Use when: proposing meeting times, or checking whether some days have room. Use it instead of reading events and computing gaps yourself. Not for listing what is booked (use calendar_list_events) or for booking a slot (use calendar_create_event once the owner picks one). Parameters:

The search range is at most 62 days and never starts before now.
day_start and day_end ('HH:MM', end later than start) bound each day.
weekdays takes names such as 'mon' or 'saturday' (the first three letters count).
timezone decides how day hours and offset-less times are read.
limit is capped at 100. Behavior:
Read-only.
Busy = timed events plus, with include_travel, their Apple travel time.
Events marked free, cancelled events and invitations the owner declined do not block time; unanswered invitations do.
All-day events never block slots: they are listed for you to judge (a trip blocks the day, a birthday does not). Returns: {free_slots, more_slots, all_day_events, not_counted_as_busy, busy_events_counted, timezone, range, now, complete}. Each slot is {start, end, minutes}: a whole opening, any part of which can be booked. Empty free_slots = no opening that long in those hours. complete=false with not_read means some calendars could not be read, so slots may not be free: tell the owner and run icloud_check_health. Errors: range in the past or too long, duration outside 5 to 1440, a malformed time or weekday.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`end`	No	Search until, same formats. A date end includes that whole day. Default start + 14 days; at most about two months.
`limit`	No	Max slots to return (1-100).
`start`	No	Search from: a date (2026-09-24), date-time, today, tomorrow or +3d. Default now; slots in the past are never offered.
`day_end`	No	Latest time of day to consider, 'HH:MM' (default 18:00; '24:00' = midnight).	18:00
`calendar`	No	Calendar name (calendar_list_calendars); omit for all.
`timezone`	No	IANA timezone for times without an offset, e.g. 'Europe/Berlin'; default the owner's.
`weekdays`	No	Only these days, e.g. ['sat', 'sun'] or ['mon','tue','wed','thu','fri']. Omit for every day.
`day_start`	No	Earliest time of day to consider, 'HH:MM' (default 09:00).	09:00
`include_travel`	No	true (default) = Apple travel time before an event also counts as busy.
`duration_minutes`	Yes	How long the opening must be, in minutes (5 to 1440).

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedSep 30, 2026

changedInput schema / properties / end / description

Previous value: -"Search until, same format. A date-only end includes that whole day. At most about two months."New value: +"Search until, same formats. A date end includes that whole day. Default start + 14 days; at most about two months."

changedInput schema / properties / start / description

Previous value: -"Search from: a date (2026-09-24) or date-time. Slots in the past are never offered."New value: +"Search from: a date (2026-09-24), date-time, today, tomorrow or +3d. Default now; slots in the past are never offered."

changedInput schema / required

Previous value: -[
-  "start",
-  "end",
-  "duration_minutes"
-]New value: +[
+  "duration_minutes"
+]

changedOutput schema / (root)

Previous value: -{
-  "additionalProperties": true,
-  "title": "calendar_find_free_timeDictOutput",
-  "type": "object"
-}New value: +null

Changed23 schema fields changedv0.7.0Sep 24, 2026

removedInput schema / properties / calendar / anyOf

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

removedInput schema / properties / calendar / default
```
Removed value: -null
```

changedInput schema / properties / calendar / description

Previous value: -"Calendar name from calendar_list_calendars. Omit to search all calendars."New value: +"Calendar name (calendar_list_calendars); omit for all."

removedInput schema / properties / calendar / title
```
Removed value: -"Calendar"
```
addedInput schema / properties / calendar / type
```
Added value: +"string"
```
removedInput schema / properties / day_end / title
```
Removed value: -"Day End"
```
removedInput schema / properties / day_start / title
```
Removed value: -"Day Start"
```
removedInput schema / properties / duration_minutes / title
```
Removed value: -"Duration Minutes"
```
removedInput schema / properties / end / title
```
Removed value: -"End"
```
removedInput schema / properties / include_travel / title
```
Removed value: -"Include Travel"
```
removedInput schema / properties / limit / title
```
Removed value: -"Limit"
```
removedInput schema / properties / start / title
```
Removed value: -"Start"
```

removedInput schema / properties / timezone / anyOf

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

removedInput schema / properties / timezone / default
```
Removed value: -null
```

changedInput schema / properties / timezone / description

Previous value: -"IANA timezone for start/end without an offset, e.g. 'Europe/Berlin'. Omit to use the server timezone."New value: +"IANA timezone for times without an offset, e.g. 'Europe/Berlin'; default the owner's."

removedInput schema / properties / timezone / title
```
Removed value: -"Timezone"
```
addedInput schema / properties / timezone / type
```
Added value: +"string"
```

removedInput schema / properties / weekdays / anyOf

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

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

removedInput schema / title

Removed value: -"calendar_find_free_timeArguments"

Addedv0.4.0Sep 24, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Annotations only declare readOnlyHint and openWorldHint; the description goes well beyond them, defining how busy time is computed, that free/cancelled/declined events do not block but unanswered invitations do, that all-day events never block, and what complete=false with not_read means (run icloud_check_health). It also enumerates error conditions. This is unusually rich behavioral disclosure for a read-only tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

It is a long description, but it is clearly sectioned (Use when / Parameters / Behavior / Returns / Errors) and front-loaded with the core purpose. The prose is dense and largely non-redundant, though the Parameters block slightly duplicates the 100%-covered schema and could be trimmed.

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?

No output schema exists, yet the description fully specifies the return shape and the meaning of each field (free_slots, more_slots, all_day_events, not_counted_as_busy, complete, etc.) and the slot structure, plus degraded-mode guidance. Nothing an agent needs to invoke or interpret this tool is 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, but the description adds operational semantics not in the schema: the 62-day cap, that the range never starts before now, that weekday names need only three letters, and that limit is capped at 100. It largely mirrors schema text otherwise, so it is a modest rather than decisive lift over the schema.

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

Purpose5/5

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

States a specific verb+resource with scope: 'Find open slots of at least duration_minutes within daily hours across the owner's calendars, with busy time and travel worked out for you.' It names what it does not do and points to the sibling tools that do those things, so an agent can distinguish it from calendar_list_events and calendar_create_event immediately.

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?

Explicit 'Use when' clause (proposing meeting times, checking whether days have room) plus an explicit routing rule: not for listing bookings (calendar_list_events) or booking a slot (calendar_create_event once the owner picks one). Use/when-not/alternatives are all present.

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

Deploy Server

calendar_find_free_time

Instructions

Input Schema

Schema Changelog

TDQS

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