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

With no annotations provided, the description must carry the behavioral disclosure burden. It does so by implying a read-only operation ('See'), declaring that the call is 'Free', and stating the auth requirement ('agent_id + api_key'). It does not explain error behavior or exact output shape, but for a simple read tool this is reasonably transparent.

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 sentence with no wasted words. It front-loads the core function, then adds cost and auth details, making it easy for an agent 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 simple two-parameter read-only tool with no output schema, the description covers the key concerns: what the call returns (services and prices), why to call it (confirm a listing is live), cost, and authentication. It is missing only minor details such as error handling or listing-status formatting, which are not critical for a tool of this complexity.

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 compensate. It does by identifying both required parameters and, importantly, noting that they come 'from marketplace_register', giving the agent a concrete source for the credentials. It could add more per-parameter detail, but the provenance clue is valuable.

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 ('See'), a clear resource ('the services you offer and their prices'), and states the intended use ('to confirm a listing is live'). It clearly distinguishes this from sibling tools like marketplace_my_sales and marketplace_services by emphasizing the agent's own offerings and pricing.

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 a clear use context: checking that one of your own marketplace listings is live. It does not explicitly name alternatives or when-not-to-use, but the purpose is specific enough that an agent can select it appropriately among the marketplace siblings.

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