nasa_apodNASA Astronomy Picture of the Day via Vigi-Sky.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
| Name | Required | Description | Default |
|---|---|---|---|
| apod | No | ||
| citations | Yes | ||
| provenance | Yes |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Output schema / requiredAdded value: +[
+ "citations",
+ "provenance"
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already provide readOnlyHint, idempotentHint, and destructiveHint=false, so the description does not need extensive behavioral disclosure. The mention of 'via Vigi-Sky' slightly adds context about data provenance, but no further traits are revealed. This is adequate given the annotation coverage.
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, well-front-loaded sentence. It is concise and immediately communicates the purpose. However, it could be slightly more informative without adding length, such as hinting at the output type.
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?
For a zero-parameter, read-only tool with solid annotations and an output schema, the description is essentially complete. It answers the core 'what does it do?' question. The existence of an output schema reduces the need to describe return values explicitly.
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 schema coverage is 100% by default. The baseline for 0 parameters is 4. The description does not need to explain parameters; 'via Vigi-Sky' is a peripheral detail about the tool's backend.
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 NASA's Astronomy Picture of the Day, specifying the source and service ('via Vigi-Sky'). It is the only APOD-related tool among 19 siblings, so there is no confusion with alternatives.
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 provides no guidance on when to use this tool versus other astronomy tools like 'aurora', 'solar', or 'object_lookup'. Without any context on use cases or exclusions, the agent must infer entirely from the name and siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.