get_image_by_id

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

With no annotations provided, the description carries full burden for behavioral disclosure. It states the tool retrieves an image, implying a read-only operation, but doesn't mention any behavioral traits like authentication requirements, rate limits, error handling, or what happens if the ID is invalid. This leaves significant gaps for an agent to understand how to use it safely and effectively.

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, efficient sentence that directly states the tool's purpose without any fluff or redundancy. It's appropriately sized for a simple retrieval tool and front-loaded with the essential information, making it easy for an agent to parse 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 (single parameter, no annotations, no output schema), the description is minimally adequate. It covers the basic purpose but lacks details on behavior, error cases, or output format, which could hinder an agent's ability to use it correctly in all scenarios. Without annotations or output schema, more context would be beneficial.

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 schema description coverage is 100%, with the single parameter 'id' clearly documented as 'Pixabay image ID'. The description adds no additional parameter semantics beyond what the schema provides, such as format examples or constraints. With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate but also doesn't need to.

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 action ('Retrieve') and resource ('a specific image by its Pixabay ID'), making the purpose immediately understandable. It distinguishes from sibling tools like 'search_images' by focusing on retrieval of a single known item rather than searching. However, it doesn't explicitly contrast with 'get_video_by_id' beyond the resource type.

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 when you have a specific Pixabay ID for an image, suggesting it's for known-item retrieval rather than discovery. However, it doesn't explicitly state when NOT to use it (e.g., vs. 'search_images' for unknown IDs) or name alternatives, leaving some ambiguity about tool selection in edge cases.

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