Chronos MCP

update_task

Update a specific task by providing its calendar and task UIDs. Modify fields such as summary, due date, priority, status, or completion percentage.

Instructions

Update an existing task. Only provided fields will be updated.

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_uid": "<calendar_uid>",
      "task_uid": "<task_uid>"
    },
    "name": "update_task"
  }
}

Input Schema

Name	Required	Description
`due`	No	Task due date (ISO format)
`status`	No	Task status
`account`	No	Account alias
`summary`	No	Task title/summary
`priority`	No	Task priority (1-9, 1 is highest)
`task_uid`	Yes	Task UID to update
`request_id`	No
`description`	No	Task description
`calendar_uid`	Yes	Calendar UID
`percent_complete`	No	Completion percentage (0-100)

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.1.0Jul 12, 2026

TDQS

A4/5.0

Behavior3/5

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

No annotations are provided, so the description bears full burden. It conveys partial update semantics ('Only provided fields will be updated') but omits details like error handling, side effects, or authentication requirements.

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 concise sentences, no redundant information, and front-loaded with the primary purpose.

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?

The tool has 10 parameters and an output schema, but the description is brief. It covers core behavior but could benefit from additional context like return value or constraints.

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 description coverage is 90%, so baseline is 3. The description adds value by stating the partial update behavior, clarifying that only provided fields change, which is not explicit in 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?

The description clearly states the verb 'Update' and the resource 'existing task', distinguishing it from sibling tools like update_event and update_journal. The behavior is clarified with 'Only provided fields will be updated.'

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not explicitly state when to use this tool versus alternatives, such as create_task or delete_task. It implies usage by context but lacks explicit guidance.

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