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

There are no annotations, so the description carries the behavioral burden. It discloses the core mutation ('list for sale') and implies an ownership prerequisite, but it does not mention side effects such as whether an existing listing is replaced, cancellation options, fees, or failure conditions.

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?

A single focused sentence with no filler. The subject, resource, venue, and pricing model are all front-loaded, making it easy to parse quickly.

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 single-action listing tool with well-documented parameters, the description provides enough operative context. It omits details like listing replacement behavior or return value, but nothing essential to invoking the tool correctly is missing.

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 the schema already documents all parameters. The description only loosely echoes priceInEth ('in ETH') and sellerAddress ('owned'), adding no new meaning beyond the schema.

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 states a specific verb and resource: 'List an owned .i domain for sale', along with the venue ('decentralized secondary marketplace') and pricing model ('fixed price in ETH'). This clearly distinguishes it from siblings like marketplace_buy_domain or marketplace_make_offer.

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 intended use is clear: to list an owned domain at a fixed ETH price. It does not explicitly contrast with alternatives such as marketplace_accept_offer or marketplace_cancel_listing, but the operation is unambiguous enough for an agent to select correctly.

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