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

Annotations already indicate readOnlyHint=true and destructiveHint=falsearke. The description adds meaningful behavioral context beyond those: it explicitly discloses a $0.005 USDC cost via x402 and clarifies support for both ERC-20 and ERC-721 standards. No contradiction with annotations.

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 two short sentences with no filler. The core action is front-loaded, the network and token standards are specified, and the cost caveat is included without bloating the text.

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 single-parameter, read-only tool with strong annotations, the description covers purpose, network, supported standards, and cost. It could mention whether the returned supply is raw or decimal-adjusted, but this is not critical for correct invocation.

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%, with the single 'token' parameter already described as an address on Base mainnet. The description adds the ERC-721 NFT clarification, but this is a minor refinement rather than substantial new meaning beyond the schema.

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 verb and resource: 'Get total supply' for an ERC-20 token or ERC-721 NFT contract on Base. It clearly identifies what the tool does and distinguishes it from sibling tools like balance, allowance, or transaction queries.

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 clearly implies when to use this tool: when an agent needs the total supply of a standardized token on Base. It does not explicitly name alternatives or state when not to use it, but no sibling tool covers total supply, so the context is sufficient.

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