read_document_image

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

Beyond annotations (readOnly, idempotent), the description discloses that it returns binary data (the only tool to do so), resizes images to 1568px on the long side, and warns that the read content is not a direct quote, requiring the '(이미지 판독)' marker. It also describes error behavior for vector-only pages, providing rich behavioral context.

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 clear sections (intro, args, returns, examples). The core purpose is front-loaded in the first sentence, and each subsequent sentence contributes essential details (format, resizing, usage, return) without redundancy. It is appropriately sized for the tool's complexity.

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?

With no output schema, the description compensates by explaining the return format (a list with image and guidance string) and noting it deviates from structured responses. It covers error cases for vector-only pages, provides usage examples, and explains how to handle the result in summaries, making it complete for an agent to call correctly.

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 already provides complete descriptions for both 'path' and 'page' (100% coverage), including the note that page is ignored for png. The description only paraphrases these, adding no new semantic meaning beyond the schema's existing clarity, so it meets the baseline but does not exceed it.

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 it reads documents without text as images, with a specific verb ('직접 판독합니다') and resource ('텍스트가 없는 문서'). It distinguishes itself from the sibling 'read_document' by explaining it is for images/scanned PDFs and specifically for grade C files, making its purpose unambiguous.

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?

Explicit usage guidance is provided in the Examples section: use when 'read_document' returns grade C, and do not use for grade A/B files, where 'read_document' is more accurate. It also explains when it is applicable (scanned PDFs, embedded images) and when it is not (vector-only pages).

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