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 names the data sources (Blockscout, Etherscan) with an on-chain RPC fallback and discloses that responses state sources and data_quality, which tells the agent how much to trust the result. It does not mention rate limits, auth needs, or pagination, so it is not exhaustive.

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 and return contents are front-loaded in the first sentence, with use cases second and provenance third. The opening sentence is dense and list-heavy, but no sentence is filler, so it is close to optimally sized.

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 two-parameter read tool with no output schema or annotations, the description covers return contents (balance, transactions, holdings, anomaly flags) and data-quality caveats well. The remaining gap is the optional chain parameter's default behavior, which an agent would have to guess.

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 0% for two parameters, so the description must compensate. It implies the chain enum's scope by saying 'Ethereum or Base' and clarifies the subject is 'any EVM address', but adds no format or default-chain detail for the required address parameter and never states what happens if chain is omitted.

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 concrete verb+resource ('Wallet due diligence for any EVM address on Ethereum or Base') and enumerates exactly what is returned: native balance, transactions with counterparties, token holdings with USD values, and anomaly flags. This scope cleanly separates it from siblings like token-risk-summary and web-search.

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?

It lists concrete use cases ('counterparty screening, airdrop eligibility checks, portfolio snapshots, or checking a wallet before transacting'), giving clear when-to-use context. It stops short of naming an alternative tool or stating when-not to use it, so it falls 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.