wellcome_image_url

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

No annotations are provided, so the description must carry the behavioral transparency burden. It discloses that the tool accepts arbitrary IIIF size strings and builds a direct URL. It does not detail error handling or return type, but for a simple pure URL builder, the main behavior is clearly stated.

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?

One sentence containing all essential information, with practical examples inline. No wasted words.

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 low complexity, no annotations, and no output schema, the description covers the primary function and size options. However, it omits explicit clarification of what 'iiifId' should be and does not state the output is a URL string, though implied. This gap prevents a perfect score.

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 has zero per-property descriptions (0% coverage), so the description must compensate. It thoroughly explains the 'size' parameter with examples, but leaves 'iiifId' undefined, relying on the parameter name and tool context. This partial coverage warrants a 3.

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 uses the imperative verb 'Build' and the specific resource 'direct Wellcome IIIF image URL', making the function unambiguous. It also includes concrete size examples, and it is clearly distinct from sibling metadata/search tools.

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 the use case: construct a direct image URL for the Wellcome IIIF API. It does not explicitly mention alternatives like download_image or wellcome_get_work, but the context makes it clear this is for URL generation. No exclusions or when-not-to-use guidance is provided, so it stops short of a 5.

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