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

With no annotations, the description carries the transparency burden. It explicitly states the tool is 'FREE' and for 'inspect before paying', indicating no cost and non-destructive behavior. This provides sufficient transparency for the user's expectations.

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 extremely concise, using a single sentence to convey purpose, cost, and value. Every word adds meaning, and it is well-structured for quick comprehension.

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 preview tool, the description provides sufficient context: what it previews (response shape/example, inputs, price) and why to use it (inspect before paying). Slightly more detail on the response format could improve completeness, but it is not essential.

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 'endpoint' parameter is described with a concrete example ('/v1/token-holders'), making the expected format clear. Although the description is minimal, the schema's 100% coverage and the example suffice for a single string parameter.

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 that this tool provides a free preview of any endpoint, showing response shape/example, inputs, and price. It effectively differentiates from sibling tools by being a generic preview tool rather than a specific data endpoint.

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 phrase 'inspect before paying' implies that this tool should be used to evaluate an endpoint before committing to a paid call. While it doesn't explicitly name alternative tools, the guidance is clear and contextually appropriate given the list of paid sibling endpoints.

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