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

With no annotations provided, the description carries the full burden and does well: it explicitly states 'No API key required' and describes the scope of information returned. It also discloses IP posture and domain relationships, giving a transparent picture of the tool's access and content. It does not explicitly state it is read-only, but that is evident from 'returns.'

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 dense paragraph that is information-rich but not overly long. Each sentence adds new detail (economics, operator, interfaces, patents), and it is front-loaded with the core purpose. Slightly more structure would help scanning, but it is far from wasteful.

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?

Given the tool has no parameters and no output schema, the description adequately explains what the response contains by enumerating the overview components. It covers functional, operational, and legal aspects, making it sufficiently complete for an agent to invoke 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?

There are zero parameters, so the baseline is 4 per the rubric. The description adds no parameter-specific meaning, but none is needed since the schema is empty and the tool requires no input.

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 'Returns a canonical, self-describing overview' of Vertical Marketplace, which is a distinct resource and action. It covers what the platform is, how buying/selling work, and economics, distinguishing it from sibling tools like browse_marketplace or sell_data.

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 implies when to use this tool (when needing an overview of the marketplace) without explicit exclusions or alternatives. It provides clear context about what it returns, but does not explicitly say when not to use it or which siblings to prefer in other scenarios.

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