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

No annotations are provided, so the description carries the behavioral burden. It discloses the $0.09 x402 payment, the live Blockscout source, and the 'one paid call instead of running your own RPC' trade-off, covering cost, provenance, and efficiency. It does not mention error cases or side effects, but the read-only nature is implied and the payment context is valuable.

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 information-dense: price and core outputs are front-loaded, followed by supported chains, use case, and source. The phrasing is slightly promotional, but every clause contributes either outputs, chains, use case, or cost/source context.

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 simple read tool with no annotations and no output schema, the description covers the essential operational facts: what it returns, which chains it supports, what it costs, and when to use it. The main gap is explicit x_payment construction, but the x402 reference is enough to make the payment mechanism discoverable.

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?

The schema already documents address and chain, and the description adds that the call is paid via x402, giving some meaning to the otherwise undocumented x_payment parameter. However, it does not explain how to construct or supply x_payment, so it only partially compensates for the 67% schema description coverage.

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 clearly enumerates the exact data returned (total supply, holder count, decimals, live USD price/market cap) and the target assets/chains, so an agent can tell it apart from sibling chain_* tools. It lacks an explicit imperative verb like 'Gets', but the field list and 'supply read' make the purpose unambiguous.

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 explicitly frames when the tool is used: by trading, valuation, and risk agents before pricing or trading a token, to size circulating supply, dilution, and holder distribution. It does not name alternative tools or state when not to use it, stopping short of full exclusions.

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