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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the shape of the answer (classification categories plus native balance) and implies a non-mutating lookup, which is useful. But it says nothing about chain coverage, what is returned for an unknown/unfunded address, or any permission/rate constraints.

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?

Two sentences, zero filler. The classification list and the usage trigger each earn their place, and the actionable instruction is front-loaded after the core identification content.

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 does the work of naming the return categories an agent should expect, which is the key gap for a lookup tool. It falls short only on unknowns — error/unknown-address behavior and supported chain scope are unstated.

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 both parameters ("0x address", "EVM chain id") are documented in the schema, so baseline is 3. The description adds no format, casing, checksum, or chain-range detail beyond what the schema already states.

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 question it answers ("What is this address?") and enumerates the concrete classifications it resolves: EOA, EIP-7702 delegated EOA, Safe multisig with threshold/owners, timelock, ERC-20 token, proxy or contract. This is specific enough to separate it from sibling check_token and scan_contract without opening either 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?

It gives an explicit trigger condition: "Use before sending funds to or trusting an address." That is real when-to-use guidance tied to a concrete risk decision. It does not, however, name any alternative (e.g. when scan_contract or check_token would be the better call), so routing between siblings is left to inference.

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