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

With no annotations, the description carries the full burden. It usefully discloses the pay-per-call model and $0.01 USDC cost, plus the per-chain endpoint paths, which are real behavioral facts. It does not state that this is a read-only operation, nor does it cover rate limits, auth requirements, or behavior for non-contract/EOA addresses.

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?

Two sentences, front-loaded with the primary purpose and return payload, followed by routing and pricing. Dense but efficient; the inline path strings are slightly cryptic but do not waste space.

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?

With no output schema and no annotations, the description compensates well by naming the three return concepts (is-contract, bytecode size, ERC-20 metadata) and the pricing model. Missing only edge-case behavior and error handling, which is acceptable for a 2-parameter read 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?

Schema coverage is 100%, so both parameters and the chain enum are already fully documented, giving a baseline of 3. The description adds the endpoint mapping for base vs polygon, but that is routing detail rather than parameter meaning, and it adds no format hints beyond what the schema's address description already provides.

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?

States a concrete verb and resource: determines whether an address is a contract, returns bytecode size and ERC-20 metadata, scoped to EVM. It distinguishes itself reasonably from the token/account siblings by focusing on contract-vs-EOA detection, though it never names a sibling to differentiate against.

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?

No explicit when-to-use guidance, no prerequisites, and no comparison to alternatives like token or account. The agent must infer from the name alone that this is for contract detection rather than balance or metadata lookup.

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