astrosPeople currently in space — name + craft (ISS / Tiangong / etc.).
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| number | Yes | Number of people currently in space | |
| people | Yes | List of astronauts/cosmonauts in space | |
| message | Yes | Response status message |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {}
+]Output schema / (root)Previous value: -nullNew value: +{
+ "properties": {
+ "message": {
+ "description": "Response status message",
+ "type": "string"
+ },
+ "number": {
+ "description": "Number of people currently in space",
+ "type": "number"
+ },
+ "people": {
+ "description": "List of astronauts/cosmonauts in space",
+ "items": {
+ "properties": {
+ "craft": {
+ "description": "Spacecraft name (ISS, Tiangong, etc.)",
+ "type": "string"
+ },
+ "name": {
+ "description": "Person's name",
+ "type": "string"
+ }
+ },
+ "required": [
+ "name",
+ "craft"
+ ],
+ "type": "object"
+ },
+ "type": "array"
+ }
+ },
+ "required": [
+ "message",
+ "number",
+ "people"
+ ],
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds value by specifying that the output includes name and craft, which is beyond the annotations. No contradictions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is a single concise sentence with no wasted words. It is front-loaded and efficiently communicates the tool's purpose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given zero parameters and the presence of an output schema, the description is complete. It tells the agent what the tool returns (name + craft) without needing further detail.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
There are zero parameters, so baseline is 4 per instructions. The description correctly indicates no parameters are needed. No additional parameter explanation required.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the tool returns people currently in space with name and craft (ISS/Tiangong/etc.). It uses a specific verb ('return' implied) and resource, and distinguishes from the sibling 'iss_now' tool which likely focuses only on ISS.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description does not explicitly state when to use this tool versus alternatives like 'iss_now'. There is no guidance on context or exclusions; the agent must infer differentiation from sibling names.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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