nasa_image_metadata

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

Annotations declare readOnlyHint=true, establishing it as a safe read operation. The description adds behavior beyond annotations by stating the return value is a URL to a JSON file, giving key context about the response. It does not contradict annotations.

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 sentence of 15 words, front-loaded with the verb 'Get', and contains no extraneous information. It is concise and well-structured.

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?

Despite no output schema, the description clearly states that the tool returns a URL to a metadata JSON file, which is sufficient for a single-parameter, read-only tool. It fully conveys the purpose and output type, so it is complete for the task at hand.

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?

Schema description coverage is 100% (nasa_id described as 'NASA media ID'). The tool description does not add additional meaning beyond the schema, but the schema already fully documents the parameter, so baseline 3 is appropriate.

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 uses a specific verb ('Get') and resource ('URL to the full EXIF/XMP/IPTC metadata JSON file') and clearly distinguishes this from sibling tools like nasa_image_asset (asset retrieval) and nasa_image_captions (captions). It precisely states what the tool does.

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 the tool is used when a NASA media ID is known and full metadata is needed. It provides clear context but does not explicitly mention alternatives or exclusionary conditions compared to sibling tools. The specificity of 'full EXIF/XMP/IPTC metadata JSON file' makes the use case evident.

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