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

No annotations are provided, so the description carries the full burden of behavioral disclosure. While it names the output (spread % as an arbitrage signal), it does not explain what data sources are used, whether it returns a single spread or a list, whether the 'token' parameter refers to a symbol or address, whether any side effects exist, or any rate-limits or network requirements. For a scanner that presumably hits external DEX/chain data, this is a notable gap.

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 concise sentence that front-loads the tool's identity and the core computation. It is efficient and wastes no words. It could earn a 5 if it used the saved space to clarify parameter usage.

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 tool with no annotations, no output schema, and two weakly documented parameters, the description leaves too much unsaid. It does not specify input formats (symbol vs address), whether one or both parameters are required, what the output structure or units are beyond 'spread %', or how this compares to the very similar sibling tools like x402-dex-arb, x402-dex-price, and x402-token-arbitrage derivatives. The description is too thin to allow reliable invocation.

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% only in the sense that both parameters have description fields, but those fields are tautological: 'Token to process' and 'Address to process' add no meaning. The description declares the tool accepts a 'token' and an 'address', but it does not clarify whether these are alternative ways to identify the same asset, whether both are required, or whether 'token' means symbol (e.g., 'ETH') or a contract address. The parameter semantics are essentially undocumented beyond the schema's empty labels.

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 communicates the core purpose ('Cross-DEX/chain price spread scanner'), the specific computation (highest vs lowest pair price -> spread %), and that it outputs an arbitrage signal. It distinguishes this from generic DEX price tools by emphasizing the spread calculation, and from the many sibling tools that are clearly price checkers (e.g., x402-dex-price, x402-token-price) by focusing on arbitrage between pairs.

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 the tool is used when a user wants to find price differences across exchanges/chains, but it never explicitly states when to use this over x402-dex-price, x402-token-price, x402-dex-scanner, or x402-token-arbitrage derivatives. It does not mention any prerequisites, such as whether a token symbol or contract address is required, or whether both parameters must be provided.

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