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

Annotations already mark this as a read-only, non-destructive, open-world operation, and the description reinforces that by stating it reads deployed bytecode. It adds valuable behavior beyond annotations by disclosing the $0.005 USDC cost via x402, which is important for invocation decisions.

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 two concise clauses that deliver the purpose, mechanism, network, and cost without wasted words. Every sentence earns its place, and the core purpose is front-loaded.

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 single-parameter, read-only tool with rich annotations, the description covers the essential facts needed to invoke it correctly: input, network, mechanism, and cost. It does not specify the exact return format, but the 'check whether' phrasing communicates the boolean classification intent sufficiently.

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%: the single `address` parameter is fully described with format, pattern, and network context. The description adds no parameter-level details beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 states a specific verb ('Check'), a clear resource ('address on Base mainnet'), and the exact outcome ('whether it is a smart contract or EOA'). It also names the mechanism ('reading deployed bytecode'), making the tool's purpose unambiguous and distinct from broader sibling tools.

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 for when the tool should be used: whenever an agent needs to distinguish a smart contract from an EOA on Base mainnet. It does not explicitly name alternatives or exclusions, but the classification purpose is concrete enough that an agent can select it appropriately.

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