download_page_image

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

With readOnlyHint=false, openWorldHint=true and idempotentHint=true already declared, the description still adds substantive context: the output is a multi-megabyte file written to disk rather than returned inline, the media URLs require no key, and the download does not consume API allowance. That is exactly the side-effect and cost information an agent needs before invoking.

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?

Front-loaded with the core action, then layered with cost, disk-write, and page-selection guidance in a logical order; every sentence carries information. Slightly prose-heavy ('turns a catalogue hit into evidence') but not padded.

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?

No output schema exists, but the description covers what is produced (a file on disk, not a return value), its size, the absence of auth or budget cost, and how to choose the right page. Nothing an agent needs to call this correctly is missing.

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?

Schema coverage is 100% and the schema already documents naid, page, object_id and destination in detail, so the baseline is 3. The description goes slightly further by framing page and object_id as mutually exclusive alternatives and pointing at the sibling tools that produce a usable object_id, adding a little routing value on top of the schema.

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?

States a specific verb and resource ('Download one page of a record') and clarifies the scope ('so it can actually be read', 'the image is written to disk rather than returned inline'). It differentiates itself from catalogue-oriented siblings by noting that a catalogue call only resolves the page list, not the image itself.

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?

Gives explicit routing: 'Use get_extracted_text or get_transcriptions to find which page carries the fact, then fetch it by the object_id they name.' It also supplies the motivating condition (a pension file can run to sixty pages, so the needed page is rarely the first), which tells the agent when this tool is the right step versus when to search first.

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