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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds meaningful behavioral context: it is 'Free, read-only', the server never holds a caller wallet, and no balance is ever returned—only public token metadata. This directly informs the user about the tool's limitations and safety profile, exceeding what annotations alone convey.

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 succinct and well-structured, opening with the primary purpose and then covering parameter formats, limitations, required fields, and supported chains in a logical flow. Every sentence provides necessary information without redundancy, making it highly scannable for an AI agent.

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-only tool with two parameters and an output schema, the description is complete. It specifies supported chains, token input format, required fields, and behavioral limitations. The output schema covers return values, so no further elaboration is needed. The description fully equips an agent to decide when and how to invoke the tool.

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%, so the baseline is 3. The description adds value by explicitly explaining the token parameter accepts a contract address (0x…) or a symbol like USDC / USDC.e where configured, and clarifies that both chain and token are required. While the schema already says this, the description reinforces it in context, slightly elevating the 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 states exactly what the tool does: 'Read ERC-20 token metadata — name, symbol, decimals, total supply — for a token contract on an EVM chain.' The verb 'Read' plus the resource and specific metadata fields clearly distinguish it from sibling tools like network.token_price, which would return price data.

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 clear context on when to use the tool and how to specify inputs, such as accepting contract address or symbol (e.g., USDC / USDC.e) where configured. It also notes that both chain and token are required and lists supported chains. However, it does not explicitly mention alternatives or exclusions beyond implying this is for metadata, not balances.

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