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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that reads come straight from the contract, that legacy bytes32 name/symbol are decoded, that a missing decimals() is flagged rather than silently assumed, and that an existence check is included. It also discloses the $0.09 via x402 pricing, which is useful behavioral context.

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 four concise sentences, each earning its place. The first sentence states the core function, the second explains the key advantage, the third covers edge-case handling, and the fourth gives positioning advice. There is no fluff or repetition, and it is well front-loaded.

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?

Given there is no output schema, the description clearly enumerates the returned fields (name, symbol, decimals, total supply, existence check). It also covers edge cases, the freshness advantage, and even pricing. This is complete for a tool of this complexity, leaving no critical information absent.

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 well describes the two main parameters (chain with allowed values/default, token as ERC-20 contract address), and coverage is 67%. The description only indirectly references the token and payment via x402, without adding detailed semantics for the x_payment parameter. Thus, the description adds marginal value beyond what the schema provides, warranting the baseline score.

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 states the tool reads ERC-20 name, symbol, decimals, and total supply directly from the contract, plus an existence check. It also distinguishes itself from indexer-backed lookups and positions it as the 'first read to make on an unknown contract,' which differentiates it from siblings like chain_token_supply.

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 description provides explicit context for when to use this tool: for tokens minted minutes ago or on chains without explorer coverage, where indexer-backed lookups fail. It also recommends it as the first read on an unknown contract. However, it doesn't explicitly name alternatives or state when not to use it, so it stops 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.