hacknplan-mcp

update_subtask

Update a sub-task in HacknPlan by renaming it or marking it as complete/incomplete.

Instructions

Update a sub-task (rename and/or mark complete/incomplete).

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": {
      "project_id": "<project_id>",
      "work_item_id": "<work_item_id>",
      "subtask_id": "<subtask_id>",
      "title": "<title>"
    },
    "name": "update_subtask"
  }
}

Input Schema

Name	Required	Description	Default
`title`	Yes
`project_id`	Yes
`subtask_id`	Yes
`is_completed`	No
`work_item_id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.0Jul 31, 2026

TDQS

B3.2/5.0

Behavior2/5

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

There are no annotations, so the description must disclose behavior, but it only says 'update' with the two actions. It does not mention the schema requirement that 'title' must be supplied even when only marking completion, nor does it describe error behavior or side effects for missing IDs.

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 one short sentence that directly states the action and scope, with no wasted words. It is front-loaded with 'Update a sub-task'.

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

Completeness2/5

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

Given the tool has 5 parameters, no output schema, and no annotations, the description is too sparse. It omits the requirement that title must always be supplied, and provides no information about return values, errors, or additional side effects, making it incomplete for a mutation tool.

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 description maps 'rename' to the title parameter and 'complete/incomplete' to is_completed, adding semantic meaning to those fields. However, it fails to explain the required-title quirk and doesn't elaborate on the ID parameters, which are nominally self-explanatory.

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 uses a clear verb 'Update' with a specific resource 'sub-task' and parenthetical scope 'rename and/or mark complete/incomplete', which distinguishes it from sibling tools like add_subtask, delete_subtask, and update_work_item.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus alternatives like add_subtask or delete_subtask. It does not state prerequisites, exclusions, or alternative tools, leaving the agent to infer usage from the tool name.

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

Deploy Server