search_stock_images

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds value by specifying that invalid or unavailable providers return an error instead of silently substituting, and that include_attribution defaults to an environment variable. However, it omits potential auth requirements, rate limits, or side effects, keeping it slightly below a perfect score.

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 well-organized with a clear first sentence stating the purpose, followed by structured Args and Returns sections. Every line adds essential detail without unnecessary verbosity. It is appropriately sized and front-loaded, making it easy for an agent to scan.

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 moderate complexity (6 parameters, multi-provider integration), the description covers all parameters and notes error handling and defaults, which is substantial. The presence of an output schema means return values need not be explained in detail. It misses a few nuances, such as the behavior when providers is omitted (default null likely means all providers) and potential authentication prerequisites, so it isn't fully complete.

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 provides only types and titles with zero description coverage, so the description must compensate. It fully explains each parameter: query string, providers with valid values and case-insensitivity, per_page, page, sort_by with allowed values, and include_attribution with its env-var default. This is comprehensive parameter documentation that far exceeds the schema's minimal information.

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: 'Search for royalty-free stock images across multiple providers.' This is a specific verb (search) plus a resource (stock images) and scope (multiple providers). It effectively distinguishes from sibling tools get_image_details and download_image, which handle post-search operations.

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 communicates the basic intent of searching images but provides no explicit guidance on when to prefer this tool over alternatives. It neither names sibling tools nor instructs the agent to use get_image_details for specific image metadata or download_image for fetching. Usage is implied by the function name rather than explicitly stated, earning a mid-range score.

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