epub_read_image

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

With no annotations, the description must fully disclose behavior. It states the return value (local path plus context), implying a read operation without side effects. However, it does not explicitly confirm that it is read-only, does not mention potential authentication requirements, or handle errors like missing images.

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 two concise sentences: the first states the action and return value, the second provides usage guidance. It is front-loaded with the core purpose and has no redundant 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 (2 parameters, simple read operation) and presence of an output schema (though not shown), the description adequately covers the tool's purpose and return value. It does not need to detail output structure since the schema is provided. However, it could be slightly more exhaustive about usage constraints.

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 description coverage is 0%, so the description must explain parameter meanings. It does not elaborate on what 'doc_id' or 'image_id' represent (e.g., document identifier, image index/ID), leaving the agent to infer from names alone. This is insufficient for correct usage.

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 returns an EPUB image local path and nearby text context. The verb 'Return' and resource 'EPUB image local path plus nearby text context' are specific. This distinguishes it from sibling tools like epub_list_images (which lists images) and pdf_read_image (for PDFs).

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 explicitly says 'Use when a multimodal LLM needs to inspect a figure, diagram, or illustration,' providing clear context for appropriate use. However, it does not explicitly exclude alternative uses or mention when not to use it, such as when only the image path is needed without context.

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