Plane MCP Server

retrieve_milestone

Retrieve a milestone from a Plane project by providing the project ID and milestone ID.

Instructions

Retrieve a milestone by ID.

Args: project_id: UUID of the project milestone_id: UUID of the milestone

Returns: Milestone object

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>",
      "milestone_id": "<milestone_id>"
    },
    "name": "retrieve_milestone"
  }
}

Input Schema

Name	Required	Description	Default
`project_id`	Yes
`milestone_id`	Yes

Output Schema

Name	Required	Description	Default
`id`	No
`title`	Yes
`created_at`	No
`updated_at`	No
`external_id`	No
`target_date`	No
`external_source`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.11Aug 7, 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 must convey the tool's behavior. It states that it returns a Milestone object, which implies a read-only operation, but it does not disclose error behavior (e.g., 404 if not found) or any permissions required. The behavioral disclosure is minimal but sufficient for a simple retrieval where the outcome is predictable.

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 compact, with a one-line summary and clearly separated Args/Returns sections. Every sentence contributes information without redundancy, making it easy to parse quickly.

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 straightforward retrieve-by-ID operation with an output schema present, the description fully explains the required inputs and the return type. It doesn't need to elaborate on behavior beyond the return value, although mentioning not-found errors could add robustness.

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?

The schema provides only string types with no descriptions (0% coverage), so the description's Args section adds critical meaning by labeling project_id as 'UUID of the project' and milestone_id as 'UUID of the milestone.' This clarifies the format and reference, compensating for the schema's lack of description.

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 opens with 'Retrieve a milestone by ID,' a specific verb+resource combination that clearly identifies the tool's function. This distinguishes it from sibling tools like list_milestones (which lists all) and create/update/delete milestones.

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 phrase 'by ID' implies this tool is for fetching a single milestone when both project_id and milestone_id are known, but it does not explicitly state when to prefer it over list_milestones or provide exclusions. No alternative tools are named, so the usage context is only implied rather than explicitly contrasted.

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

Deploy Server