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

Annotations already declare readOnlyHint=true and idempotentHint=true, indicating a safe, read-only operation. The description adds context about the library's scope (140K+ items, missions, telescopes) but does not disclose additional behavioral traits like pagination behavior or rate limits. With annotations covering safety, this is adequate but not rich.

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, concise sentence that effectively communicates the tool's purpose and key features. It is front-loaded with the action and includes relevant details without unnecessary verbosity.

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 thorough schema, annotations, and presumed output schema (has_output_schema: true), the description is fairly complete. It mentions the content types, size, and that metadata and download links are returned. Minor omission: no mention of default page size or pagination behavior, but these are likely covered by the output schema.

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?

Input schema covers all 5 parameters with detailed descriptions (100% coverage). The description adds no extra meaning beyond what the schema provides, so the baseline of 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 clearly states the tool searches the NASA Image and Video Library with specific details about content types and size. However, it does not explicitly differentiate from other NASA tools like nasa.asteroids.feed or nasa.astronomy.apod, leaving potential ambiguity for an AI agent.

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 searching NASA media but provides no explicit guidance on when to use this tool versus alternatives, nor does it mention exclusions or specific contexts. The agent must infer the appropriate use from the tool's name and general purpose.

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