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

Even though annotations already mark this as readOnly and idempotent, the description adds substantial behavioral context beyond them: the connector holds no wallet, 165 tools are free, paid tools settle via x402 in USDC, and the return shape is included. This is exactly the kind of operational detail an agent needs.

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 dense but front-loaded with the core purpose and every sentence carries relevant information. The long list of chains and return fields is justified because this is a reference-style informational tool.

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 zero-parameter read-only info tool, the description is complete: it explains what the tool covers, how payment works, what rails are supported, how to check wallets, and what the response contains. Nothing else is needed for an agent to invoke it correctly.

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 tool has zero parameters, so the baseline is 4. There is nothing for the description to add about parameters, and the schema already fully covers this by having an empty properties object.

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 clear subject: how paying for Agent402 tools works and how to manage a wallet. It goes beyond the title by enumerating the free-vs-paid split, wallet configuration, rails, and balance checking, which fully distinguishes it from the sibling tools.

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 gives clear context for when this informational tool is relevant and even points to catalog.call for balance/history queries. It does not explicitly state when not to use it or compare it to server.describe, but the usage context is unambiguous enough for an agent.

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