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

Beyond annotations that already declare readOnly and non-destructive behavior, the description discloses important behavioral details: interface support is read from the contract's own declaration before inference, the ordering matters because NFTs also implement totalSupply(), and the call is priced at $0.002 per call over x402 with a free daily allowance. This goes well beyond what annotations provide.

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 every sentence earns its place: it states the core question, details the outputs, explains the interface-reading logic, gives the required input, and covers pricing and authentication. It is front-loaded with the main purpose and avoids filler.

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 one well-documented parameter and an output schema present, the description provides everything needed to invoke the tool correctly: the address to inspect, the Base network context, the standard-detection logic, and the billing/header requirements. No critical behavioral or usage gap remains.

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 schema already documents the single address parameter with 100% coverage, so the baseline is 3. The description adds value by specifying that the address must be on Base and that it can be either a contract or a plain wallet, clarifying what the tool will inspect. That extra context justifies a 4.

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 identifies the tool's purpose: determining whether a Base address is a contract or plain wallet and identifying the token standard (ERC-721, ERC-1155, ERC-20) plus name, symbol, decimals, and code size. It uses a specific verb-like framing ('Is it a contract, and what standard does it follow?') and provides enough detail to distinguish it from sibling tools such as contract_abi or token_info.

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 gives clear context on when to use the tool—when you need to identify what sits at a Base address and which standard a contract follows. It also provides an interpretive guideline: interface support is read from the contract's declaration first and only inferred when absent, because NFTs answer totalSupply() too. It does not explicitly name alternative tools or state when not to use it, so it stops short of a 5.

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