Astronomer MCP Server

create_celestial_body

Create a new celestial body record linked to a star system by specifying its name, optional themes, and physical description for astrophysics modeling.

Instructions

Create a new celestial body record associated with a star system.

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": {
      "star_system_id": "<star_system_id>",
      "name": "<name>"
    },
    "name": "create_celestial_body"
  }
}

Input Schema

Name	Required	Description
`name`	Yes	Name of the celestial body (e.g. 'TRAPPIST-1e', 'Europa')
`themes`	No	Thematic planetary tags (e.g. ['habitable zone', 'rocky terrestrial', 'water vapor'])
`description`	No	Description of physical characteristics, orbital radius, atmosphere, and composition
`star_system_id`	Yes	Star System ID

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Nov 13, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations supplied, the description carries the full behavioral burden and discloses almost nothing: it does not say whether star_system_id must reference an existing system, whether the call fails on a missing parent, whether names must be unique, or what the response contains (e.g. the new ID). The only behavioral hint is the implicit foreign-key relationship to a star system.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with the verb and the created resource stated first and no filler. It is efficient, though its brevity is also the source of the missing behavioral detail.

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?

For a 4-parameter mutation tool with no annotations and no output schema, the description should cover prerequisite validity of star_system_id and the shape of a successful result. Neither is addressed, so an agent cannot predict failure modes or what comes back after creation.

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?

Schema description coverage is 100%, with each property documented including examples for name and themes, so the schema does the heavy lifting and baseline 3 applies. The description adds only the notion that star_system_id links to a star system, which the schema already conveys through its 'Star System ID' description.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb ('Create') and resource ('a new celestial body record') plus a scoping clause tying it to a star system. An agent can tell this apart from get/update/delete siblings by verb alone, though it does not name any of them.

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?

There is no guidance on when to choose this over clearly related siblings such as upsert_celestial_bodies_batch, populate_celestial_bodies_bulk, or create_star_system first. No preconditions, exclusions, or ordering are stated, leaving the agent to infer usage entirely.

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

Deploy Server