notion-calendar-mcp

update_calendars

Rename or recolor calendars by patching their metadata (summary, color, selection) through a single batch mutation.

Instructions

Patch calendar metadata (summary, color, selected, …). POST /v2/updateCalendars {mutations:[{provider, accountId, calendarId, calendarData, colorRgbFormat?, variant?}]}. mutations_json: JSON array. Call when renaming/recoloring calendars. Summary first.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "mutations_json": "<mutations_json>"
    },
    "name": "update_calendars"
  }
}

Input Schema

Name	Required	Description	Default
`mutations_json`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 8, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already indicate readOnly=false and destructive=false, and the description adds the PATCH semantics plus a batch mutation array, signaling multiple calendars can be updated in one call. It doesn't cover permissions or reversibility, but for a non-destructive metadata patch the annotation coverage lowers the bar.

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

Conciseness4/5

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

The description is dense but brief, front-loading the action and including only the endpoint, payload shape, and usage trigger. The phrase 'Summary first' is cryptic and adds confusion, slightly marring an otherwise efficient structure.

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?

For a single-parameter mutation tool with no output schema, the description provides the HTTP endpoint, body structure, and parameter format. The main gap is whether mutations_json should be passed as a stringified JSON array or a raw array; the schema type 'string' implies stringification, but the description doesn't explicitly state it.

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

Parameters5/5

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

Schema coverage is 0%, so the description carries the full burden for the lone mutations_json parameter. It explicitly defines it as a JSON array and specifies the mutation object fields (provider, accountId, calendarId, calendarData, colorRgbFormat?, variant?), which is far beyond what the schema provides.

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 action ('Patch') on a specific resource ('calendar metadata') with concrete examples (summary, color, selected). The HTTP endpoint further disambiguates it from sibling tools like update_events or update_holds, making the tool's role immediately recognizable.

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?

Provides an explicit trigger for use: 'Call when renaming/recoloring calendars.' It doesn't name alternatives or conditions to avoid, but the usage context is clear enough for an agent to select it appropriately among siblings.

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