Todoist MCP Server

update-tasks

Destructive

Update existing Todoist tasks with new content, dates, priorities, or assignments. Send only changed fields to prevent unintended overwrites.

Instructions

Update existing tasks including content, dates, priorities, and assignments. Send only the fields that change.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`tasks`	Yes	The tasks to update (max 25).

Output Schema

TableJSON Schema

Name	Required	Description
`tasks`	Yes	The updated tasks.
`failures`	Yes	Tasks that could not be updated, with the reason for each. A failure here does not affect the other tasks in the batch.
`totalCount`	Yes	The total number of tasks updated.
`updatedTaskIds`	Yes	The IDs of the updated tasks.
`appliedOperations`	Yes	Summary of operations performed.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv13.3.1Sep 22, 2026

TDQS

A4/5.0

Behavior3/5

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

Annotations already signal a mutating and destructive operation (destructiveHint true, readOnlyHint false), so the description only needs to add context beyond that. It adds the useful partial-update behavior, but it does not disclose side effects such as project or section moves lifting a task out from under its parent.

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 short sentences with no filler: purpose is front-loaded and the key usage rule immediately follows. Every word earns its place.

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 batch tool with exhaustive schema documentation, an output schema, and safety annotations already present, the description carries the core guidance efficiently. It lacks explicit sibling routing and side-effect warnings, but those are partially covered by schema descriptions and sibling tool names.

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?

The tasks parameter is fully documented by the schema (100% coverage) with per-field descriptions for id, content, dueString, priority, labels, and more. The description adds no parameter-level meaning beyond what the schema already provides, so the baseline score 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 names the exact operation (update), the resource (existing tasks), and the main updatable areas (content, dates, priorities, assignments). The phrase 'existing tasks' distinguishes it from add-tasks, and the resource name separates it from sibling tools like update-reminders and update-labels.

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 clear context by saying the tool updates existing tasks and provides a concrete invocation norm: 'Send only the fields that change.' However, it does not explicitly name alternatives or exclusions, so it falls just short of full routing guidance.

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