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

Beyond the annotations (readOnly, idempotent, openWorld), the description discloses critical behavioral traits: it is a paid call requiring x402 payment, the first call returns a 402 challenge, payment is forwarded as a header, and nothing is charged for the 402 or failed calls. These details are essential for correct usage and are not present in the annotations.

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 dense but well-organized: it opens with the paid nature, lists the data points, contrasts with alternatives, explains the payment flow, and lists error conditions. Each sentence contributes value; it is slightly long but not verbose, warranting a strong score.

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 sufficiently explains what data is returned (price, liquidity, volume, market cap, safety) and the conditions under which errors occur. Since an output schema exists (though not shown), the absence of a detailed return format is acceptable. The description provides enough context for an agent to decide whether to call this tool.

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 input schema already provides comprehensive descriptions for all parameters (chain, token, payment), including the payment payload format. The tool description does not add additional parameter-specific semantics beyond what the schema states, so it receives the baseline score for full schema coverage.

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's purpose: providing a comprehensive ERC-20 report combining price, liquidity, volume, market cap, DEX pair, and safety verdict. It explicitly contrasts with token_price and token_safety, making its unique value proposition obvious.

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?

It explicitly tells when to use this tool instead of chaining token_price + token_safety. It also details the payment flow: first call without payment returns a 402 with instructions, second call with payment completes the request. Error codes (400, 404, 502) are explained with the condition that no charge occurs for failed calls.

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