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

With no annotations, the description carries the full burden and does well: it discloses the paid x402 model with a precise price ($0.005 USDC on Base) and enumerates the returned fields, which is critical since there is no output schema. It is implicitly a read-only lookup. Minor gaps remain — no statement about behavior for a non-existent/EOA address (partial result vs error) or any rate/response-time notes.

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?

Front-loaded with the core purpose in the first clause, followed by a dense but scannable enumeration of returned data and a separate cost sentence. No filler, though the return-field list is long; it earns its length because no output schema exists to carry that information.

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 one-parameter read tool with no annotations and no output schema, the description covers purpose, chain scope, return surface and payment cost — everything needed to decide to call it and interpret results. The remaining gap is failure semantics for invalid or non-contract addresses and any note on output format beyond field names.

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% and the single address parameter carries its own description and a ^0x[0-9a-fA-F]{40}$ pattern, so the schema already does the work. The description adds only that the address must be on Polygon PoS, which is marginal beyond the schema. Baseline 3 applies for a fully documented single 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?

States a specific verb ('Identify what lives at') plus the exact resource scope (a Polygon PoS address) and enumerates the concrete outputs: EOA vs contract, EIP-7702 delegation, ERC-20/721/1155, name/symbol, proxy implementation and admin, bytecode size, nonce and POL balance. The chain qualifier cleanly separates it from eth_contract_info, base_contract_info and the other *_contract_info siblings, and the descriptive scope separates it from polygon_wallet_profile / polygon_token_snapshot.

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 enumeration of outputs strongly implies when to reach for it (address classification and token/proxy inspection on Polygon), but no explicit when-to-use or when-not-to-use statement exists and no sibling is named as an alternative. An agent must infer that polygon_wallet_profile is the choice for transactional history and polygon_token_snapshot for token-market data rather than learn it here.

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