nasa_epic_latest

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

No annotations are provided, so the description carries the full burden. It mentions the instrument and L1 point but does not disclose update frequency, data freshness, rate limits, or authentication requirements. Behavior is straightforward but lacks depth.

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 extremely concise with two focused sentences. It front-loads the key purpose and immediately lists output contents, with no wasted words.

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 the simplicity of the tool (no parameters, no output schema), the description adequately covers what the tool returns. It could mention the image format or coordinate system for completeness, but the provided list is sufficient for an agent to understand the tool's role.

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?

The tool has zero parameters, and schema coverage is 100%. The description adds meaningful context by specifying the return values (image URL, caption, coordinates, sun position), which is sufficient for a parameterless tool.

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 retrieves the latest full-disk Earth photograph from DSCOVR's EPIC instrument and lists the returned data (image URL, caption, coordinates, sun position). It distinguishes itself from siblings like nasa_epic_archive and nasa_epic_date by specifying 'latest'.

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 implies usage for the most recent image but does not explicitly state when to use this tool over alternatives, nor does it provide exclusions or prerequisites. Usage context is inferred from the name and description.

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