get_astronomy_photo

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

No annotations are provided, so the description carries the full burden. It mentions the tool fetches data from NASA's APOD service and describes the return format, but lacks details on rate limits, authentication needs, error handling, or data freshness. It adequately covers basic behavior but misses operational constraints.

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 efficiently structured with a clear purpose statement followed by labeled sections for arguments and returns. Every sentence adds value without redundancy, and it's front-loaded with the core functionality, making it easy to scan and understand quickly.

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 tool's low complexity (1 optional parameter) and the presence of an output schema (which handles return values), the description is largely complete. It covers purpose, parameter usage, and return content. However, it could improve by addressing behavioral aspects like rate limits or error scenarios, which are not covered by annotations or 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?

With 0% schema description coverage for the single parameter, the description compensates by specifying the parameter's purpose ('Optional date in YYYY-MM-DD format'), default value ('default: today'), and format. This adds meaningful context beyond the bare schema, though it doesn't detail edge cases like invalid dates.

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 specific action ('Get NASA's Astronomy Picture of the Day') and identifies the exact resource (APOD). It distinguishes itself from sibling tools like 'get_mars_rover_photos' or 'query_nasa' by focusing on a specific NASA service rather than general queries or other NASA data sources.

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 retrieving APOD data, but provides no explicit guidance on when to use this tool versus alternatives like 'query_nasa' or 'search_nasa_images'. It lacks any mention of prerequisites, exclusions, or comparative context with sibling tools, leaving usage decisions to inference.

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