nasa_image_search

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

Annotations include readOnlyHint=true, which already signals a safe read operation. The description adds context about the scope (image, video, audio) and available filters but does not disclose additional behavioral traits such as pagination limits, response shape (e.g., metadata only vs. direct files), or whether any parameters are mutually exclusive. With annotations covering safety, this meets the baseline but adds limited extra value.

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 two sentences, front-loaded with the primary action and resource. Each sentence contributes: the first states the core purpose, the second enumerates filter capabilities. No filler or redundant phrasing.

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 search tool with 13 parameters and no output schema, the description gives a useful overview of capabilities and filter categories. It does not explain response format or pagination behavior, but the readOnlyHint and the schema (which fully documents each parameter) reduce the need for that detail. The description is sufficient for an agent to select the tool for a broad media search, though it could mention that it returns search results rather than actual media assets.

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 has 100% description coverage, so the baseline is 3. The description adds a light summary of parameter families (keyword, center, media type, year range) but does not provide deeper semantics beyond what the schema already documents. It repeats examples like center codes already present in the schema.

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 function with a specific verb ('Search'), a resource ('NASA's image, video, and audio library'), and a scope (filterable by keyword, center, media type, year range). This distinguishes it from sibling tools like nasa_image_asset or nasa_image_metadata, which imply retrieval of specific assets rather than general searching.

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 clear context for when to use this tool: when searching NASA media. It lists the main filter dimensions, giving the agent an idea of the types of queries it can serve. However, it does not explicitly name alternative tools or exclude cases (e.g., 'use nasa_image_asset to fetch the actual image file'), so it falls short of a perfect score for explicit guidance.

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