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

With no annotations, the description carries the full burden. It discloses cost per chapter, the payment link requirement, that generation begins only after payment, and points to get_job_status for tracking. It also mentions tax. This covers the key behavioral aspects (paid, async) that an agent needs to know, beyond what the schema provides.

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?

Three sentences, each with a distinct purpose: stating the action, quoting cost, and explaining the payment-tracking flow. No redundant information, and the key operational constraints are front-loaded. This is a model of concise, effective description.

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?

For a complex operation involving paid generation and async follow-up, the description covers the essential flow: cost, payment requirement, and tracking via get_job_status. It doesn't detail return structure (no output schema) or failure modes, but for an initiation tool it is sufficiently complete for an agent to call it correctly and know what to do next.

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 100%, so all parameters are already documented in the schema. The description adds no parameter-specific details beyond what the schema provides; it only mentions cost relative to chapter_count, but that's not a parameter explanation. Baseline of 3 is appropriate given high 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 the tool's action: 'Start generating a complete multi-chapter eBook using AI.' It also includes cost and payment details, making the purpose unambiguous. However, it does not explicitly differentiate from sibling tools like list_genres or download_epub_url, though the core action is distinct enough that an agent can infer its role.

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 provides process guidance: it returns a payment link and instructs to use get_job_status after payment. This implies this tool is the entry point for generation, but it doesn't explicitly state when to use this versus alternatives, nor does it mention exclusions (e.g., 'use list_genres first' or 'do not use for downloading'). It gives some context but not explicit routing.

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