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

Annotations already cover read-only and non-destructive behavior, so the bar is lower. The description adds valuable behavioral detail: it returns unsigned calls and never signs or submits. It clearly explains what the tool does and does not execute.

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?

Two tight sentences front-load the core behavior and safety boundary. Every phrase adds meaningful information, and nothing is redundant.

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 fully conveys what the tool returns, which marketplace it targets, and the fact that it does not execute the transaction. With the output schema and annotations covering the rest, an agent has enough to call and use it 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 describes all four parameters with patterns and field-level explanations, so the description does not need to re-explain them. The description only reinforces the overall context of token approval and listing without adding parameter-specific meaning.

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 uses a specific verb ('Prepare'), names the exact resource ('token approval and list()'), and scopes it to the verified mainnet marketplace. It also clarifies the output as unsigned calls, making it unmistakable what the tool does.

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 gives clear context: this is for creating unsigned mainnet marketplace listing actions, and it explicitly contrasts itself with signing or submitting. It does not explicitly say when to choose this over prepare_listing or the internal variants, so it stops short of full alternative routing.

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