epub_ebook_structure_unpacker

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

With no annotations provided, the description must carry the full burden of behavioral disclosure. It mentions the cost (0.030 USDC) and the transformation to markdown, but does not disclose any side effects, required input validity, error handling, or whether the operation is read-only. It also doesn't specify if the input EPUB is consumed or just read, leaving some ambiguity.

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, information-dense sentence that front-loads the core functionality and immediately states the output format. The additional cost note is brief and useful. There is no wasted text, and it is well-structured for quick comprehension.

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?

The description covers the main purpose and output but omits important context such as error conditions (e.g., malformed EPUBs), input format expectations beyond 'EPUB', and whether the tool handles DRM or large files. Since there is no output schema, the agent has no information about the exact structure of the returned markdown, but the description implies a simple list of chapters. This is adequate but not exhaustive.

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 input schema already provides descriptions for both parameters (payload and paymentSignature) with 100% coverage. The tool description does not add any parameter-specific guidance beyond what the schema states, so it neither enhances nor detracts from the schema's clarity. This is the baseline for full schema coverage.

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 a specific action (unpacks), a specific resource (EPUB digital publications), and the key components it resolves (container XML, spine reading order, table-of-contents) into a clear output (linear markdown chapters). This is unambiguous and distinguishes it from unrelated sibling 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 clearly indicates when to use this tool: when you have an EPUB publication and need it as linear markdown chapters. It does not explicitly mention alternatives or exclusions, but the purpose is specific enough that an agent would know when it applies. It also includes a cost note, which is useful for decision-making.

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