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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered by structured data. The description adds genuinely non-derivable behavioral context: this call is metered at $0.004 USDC via x402, which materially affects invocation decisions. It stops short of describing failure modes or rate/latency behavior, so it is not a 5.

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 purpose question is front-loaded and the rest is dense, information-bearing enumeration with no filler sentences. It reads as one over-packed run-on list and the pricing note is tacked on at the end, which slightly weakens structure, but nothing is wasted.

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, the description carries the return-value burden and does so thoroughly (standards, proxy types, owner, verification, risky function list). Combined with the payment disclosure, an agent knows what it gets and what it costs; only address formatting and any pagination/truncation of the function list are unaddressed.

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 50% — 'chain' is documented with its allowed values in the schema, but 'address' has no description at all. The description never mentions either parameter, neither the expected address format (checksummed? hex length?) nor the chain default, so it fails to compensate for the uncovered required parameter.

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 inspection target ('What is this address? Wallet or contract') and then enumerates the exact analysis surface: token standard detection, proxy patterns (EIP-1967, beacon, minimal clone, EIP-7702), owner, Sourcify verification, and the function list. This enumeration clearly differentiates it from siblings like address_validate, address_verify, contracts, or token_scan without needing to open any schema.

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?

There is no explicit when-to-use / when-not-to-use guidance and no alternative tool is named, despite many plausible siblings (address_validate, address_verify, abi_decode, token_scan, report_contract_audit). The only contextual signal is the price, which implies deliberate/paid use but does not tell an agent when to prefer this tool over another.

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