TimeTree MCP Server

update_calendar_labels

DestructiveIdempotent

Rename or recolor calendar labels for everyone and return all labels; only specified labels change, while omitted labels are preserved.

Instructions

Rename or recolor calendar labels for everyone in the calendar, and return all labels. Only the labels you pass change; the others are read first and kept. Label IDs come from get_calendar_labels.

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": {
      "calendar_id": "<calendar_id>",
      "labels": "<labels>"
    },
    "name": "update_calendar_labels"
  }
}

Input Schema

Name	Required	Description	Default
`labels`	Yes	Labels to update/merge. Omitted labels are preserved.
`calendar_id`	Yes	The calendar ID from list_calendars (numeric string; numbers are also accepted)

Output Schema

Name	Required	Description	Default
`labels`	Yes
`message`	No
`success`	Yes
`calendar_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.7.0Oct 22, 2026

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "calendar_id": {
+      "type": "number"
+    },
+    "labels": {
+      "items": {
+        "properties": {
+          "color": {
+            "type": [
+              "number",
+              "null"
+            ]
+          },
+          "default_color": {
+            "type": [
+              "number",
+              "null"
+            ]
+          },
+          "id": {
+            "type": "number"
+          },
+          "name": {
+            "type": "string"
+          },
+          "order": {
+            "type": [
+              "number",
+              "null"
+            ]
+          }
+        },
+        "required": [
+          "id",
+          "name"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "message": {
+      "type": "string"
+    },
+    "success": {
+      "type": "boolean"
+    }
+  },
+  "required": [
+    "success",
+    "calendar_id",
+    "labels"
+  ],
+  "type": "object"
+}

Changed2 schema fields changedv0.4.0Oct 3, 2026

changedInput schema / properties / calendar_id / description

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

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

First observedv0.3.0May 27, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already declare non-readOnly, destructive, idempotent and open-world, and the description adds the merge/read-modify-write behavior and the scope of impact on all calendar members. That is meaningful context beyond the structured hints, though it says nothing about failure modes or concurrency.

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 short sentences, front-loaded with the action and scope, followed by merge semantics and ID provenance. Nothing is redundant or padded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists and the schema fully documents parameters, so the description only needs to carry the merge semantics and ID source — both of which it does, alongside annotations covering the safety profile.

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%, so both calendar_id and the nested label fields are already documented. The description adds only the provenance of label IDs; the merge rule it mentions is already stated in the schema's labels description, so baseline 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?

States specific verbs (rename/recolor) and the exact resource (calendar labels), plus the audience scope ('for everyone in the calendar'). It is unmistakably distinct from the sibling get_calendar_labels, which it names as the ID source.

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 directs the agent to get_calendar_labels for IDs, which is the key prerequisite, and clarifies that omitting a label leaves it untouched. It does not state explicit when-not conditions, but the usage context is clear.

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