chain_state

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

With no annotations, the description carries the full burden, and it does disclose the notable behavioral trait that this is a paid operation with a specific price and payment rail (x402 on Base). It omits anything about auth/payment prerequisites, failure or refund behavior, or rate limits, so the disclosure is partial.

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?

A single compact line, front-loaded with the resource and returned data, then the cost. Every clause carries information, though the parenthetical stacking of '(paid) (costs 0.05 USDC on Base via x402)' is slightly redundant.

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 4-param paid tool with no output schema, listing the returned fields is valuable, and the pricing disclosure is present. However, with no annotations and no output schema, the description should also cover prerequisites, the tokens/confirmNewPurchase interaction, and sibling differentiation, which it does not.

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 coverage is 75% and the schema already documents tokens, address, and the confirmNewPurchase purchase-confirmation flag. The description confirms the ERC-20 balance read maps to the tokens param and the 5-chain scope matches the chain enum, but adds no format or semantic detail 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?

States a specific resource (wallet/contract state) and enumerates what is returned: native balance, nonce, EOA/contract status, and ERC-20 balances across 5 EVM chains. Clear verb+resource, though it never names or distinguishes itself from the apparent siblings chain_info and chain_call.

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 flags that ERC-20 balance reads are paid (0.05 USDC on Base via x402), which hints at cost-sensitive usage, but it gives no explicit when-to-use guidance and no routing versus chain_info or chain_call. An agent is left to infer which chain tool to pick.

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