balances

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful domain context (gas is billed on the gas limit, MON is required to transact) and the default-wallet behavior, but says nothing about failure modes for a malformed address, response shape, or rate limits.

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?

Front-loaded with the core action and resource in the first sentence, so an agent gets the gist immediately. The trailing gas-billing aside is somewhat tangential for a read tool, but it is short and operationally relevant rather than filler.

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 2-parameter read-only tool with no output schema, the description covers what is returned (USDC, MON, parked USDC) and the default target wallet, which is what an agent needs to call it correctly. Only minor gaps remain around result formatting and chain/address handling.

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 100% with detailed patterns and descriptions for both parameters, so the baseline is 3. The description reinforces the default-wallet behavior and hints that the returned 'parked USDC' relates to the agentId/ERC-8004 identity, but adds no new syntax or formatting 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 verb and resource (read a wallet's USDC and MON balances) and adds scope detail the name alone doesn't carry: default server wallet, plus USDC parked for withdrawal. It is clearly distinguishable from siblings like get_pending_actions or get_bounty, which retrieve different resources.

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?

Usage is implied rather than stated: the gas explanation tells the agent why balances matter ('a wallet with USDC but no MON cannot send any transaction'). There is no explicit when-to-use or when-not-to-use rule, and no named alternative tool for cases like checking another agent's balance history.

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