nasa_image_captions

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

The readOnlyHint annotation already signals a safe, non-destructive operation, and the description adds that the output is a URL to an SRT file. However, it does not disclose details such as availability of captions for all videos, possible error cases, or whether the URL is directly usable without additional authentication, which would enhance transparency.

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, focused sentence that is front-loaded with the primary action and outcome. It contains no filler, no repetition of the tool name, and every word contributes to the tool's purpose.

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 tool with one required parameter and no output schema, the description sufficiently conveys the input, the action, and the output (a URL). It is slightly sparse on context like how to obtain the NASA ID or when captions might be unavailable, but given the tool's simplicity, the description is complete enough for accurate invocation.

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 single parameter 'nasa_id' has a complete schema description ('NASA video ID'), achieving 100% schema coverage. The tool's description adds no additional semantic detail beyond what the schema already provides, so it meets the baseline without needing to compensate.

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 action ('Get the URL') and its specific resource ('SRT subtitle/captions file for a NASA video asset'), which is distinct from the sibling NASA image tools that focus on assets or metadata. It leaves no ambiguity about what this tool does or the kind of item it targets.

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 implicitly communicates when to use it: when a caption/subtitle file URL for a NASA video is needed. It does not explicitly name alternatives or exclusion criteria, but the narrow purpose and presence of a dedicated NASA ID parameter provide clear context for the intended use.

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