nasa_image_asset

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

The description supplements the readOnlyHint annotation by specifying the exact output (all rendition URLs with the five size categories). It does not disclose edge cases like missing renditions or rate limits, but for a simple read operation the annotation plus this output detail are adequate.

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?

Two short, front-loaded sentences convey the tool's purpose and prerequisite without unnecessary detail. Every clause adds value.

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 single-parameter read tool with no output schema, the description is concise and complete: it states what is returned, what input is needed, and where to obtain the input. It could mention error behavior if the nasa_id is invalid, but that is a minor gap.

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 input schema fully documents the nasa_id parameter with a descriptive example. The description adds the source hint 'from search results,' which is useful but not essential, so it meets the baseline for 100% schema coverage without adding significant new meaning.

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's purpose: retrieving all rendition URLs (original, large, medium, small, thumbnail) for a NASA media asset. This specific verb-object pairing and enumeration of output distinguish it from sibling tools like nasa_image_search or nasa_image_metadata.

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 a clear prerequisite and usage directive: 'Use a nasa_id from search results.' This tells the agent when to call this tool, but it does not explicitly list when not to use it or name alternative tools.

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