search_images

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions that the tool 'Search for images on Pixabay' and returns 'Search results with image URLs and metadata,' which implies a read-only operation but lacks details on permissions, rate limits, pagination behavior, or error handling. For a tool with 8 parameters and no annotations, this is insufficient.

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-structured and appropriately sized, with a clear purpose statement followed by detailed parameter explanations and a returns section. Every sentence adds value, but it could be more front-loaded by emphasizing the tool's core function before listing parameters. However, it avoids redundancy and is efficiently organized.

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 complexity (8 parameters, no annotations, but with an output schema), the description is mostly complete. It thoroughly documents parameters and states the return format, and the output schema likely covers return values, reducing the need for detailed output explanations. However, it lacks behavioral context like rate limits or authentication needs, which are important for a search tool.

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 description adds significant meaning beyond the input schema, which has 0% schema description coverage. It explains each parameter's purpose with examples and constraints (e.g., 'query: Search term (e.g., "yellow flowers", "cat")', 'per_page: Number of results per page (3-200)'), compensating fully for the schema's lack of descriptions. This is essential for understanding how to use the parameters correctly.

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 purpose: 'Search for images on Pixabay.' It specifies the verb ('search') and resource ('images on Pixabay'), making the action and target explicit. However, it does not differentiate from its sibling tool 'search_videos' (which searches videos on Pixabay), so it lacks sibling differentiation.

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 no guidance on when to use this tool versus alternatives. It does not mention the sibling tool 'search_videos' or any other tools, nor does it specify contexts or exclusions for usage. The only implied usage is for searching images, but no explicit alternatives or constraints are provided.

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