HacknPlan MCP Server

create_subtask

Creates a subtask and links it to a parent user story in a single API call, inheriting board settings when not specified. Supports automatic resolution of category, importance, and tags from names.

Instructions

Create a subtask linked to a parent user story in a single call. Wraps create_work_item + set_work_item_parent. Inherits board from parent if not specified. Supports name resolution for category, importance, and tags.

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": {
      "parentWorkItemId": "<parentWorkItemId>",
      "title": "<title>",
      "categoryId": "<categoryId>"
    },
    "name": "create_subtask"
  }
}

Input Schema

Name	Required	Description
`title`	Yes	Title of the subtask
`tagIds`	No	Tag IDs (numbers) or names (strings): [1, 8] or ['vulkan', 'performance']
`boardId`	No	Board/sprint ID (inherits from parent if not specified)
`projectId`	No	The project ID (optional if HACKNPLAN_DEFAULT_PROJECT env var set)
`categoryId`	Yes	Category ID (number) or name (string): 'programming', 'design', 'writing', 'ideas', 'bug'
`description`	No	Detailed description of the subtask
`estimatedCost`	No	Estimated effort/points
`assignedUserIds`	No	User IDs to assign to this subtask
`parentWorkItemId`	Yes	Parent user story ID to link this subtask to
`importanceLevelId`	No	Importance level ID (number) or name (string): 'urgent', 'high', 'normal', 'low'

Schema Changelog

Changes observed during successful MCP inspections.

First observedv7.2.0Jul 13, 2026

TDQS

A4.4/5.0

Behavior4/5

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

No annotations provided, so the description carries full burden. It discloses key behaviors: wrapping two operations, inheritance of board, and name resolution. It could be more explicit about side effects (e.g., modifying parent's children list) but is adequate.

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 concise sentences, front-loaded with the core purpose. No wasted words; every sentence adds value.

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?

Given 10 parameters, no output schema, and no annotations, the description is fairly complete. It explains the main functionality and key behaviors, though it omits return value and error handling.

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%, baseline 3. The description adds meaning beyond schema by explaining board inheritance and name resolution for category, importance, and tags, enhancing clarity for those parameters.

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 action ('Create a subtask linked to a parent user story') and distinguishes it from siblings like create_work_items by specifying it wraps two operations and handles parent linking in a single call.

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?

The description explains when to use this tool (linking a subtask to a parent in one call) and mentions inheritance of board and name resolution, but does not explicitly state when not to use it or compare with alternatives among siblings.

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

Deploy Server