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

With no annotations, the description carries the full burden. It usefully discloses the return contents (native ETH and USDC) and the payment model ($0.001 USDC on Base via x402), which is real behavioral context. It omits failure modes, rate limits, and whether a charge applies on failed calls, so the safety/cost profile is only partially covered.

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?

Three tight sentences with the core purpose front-loaded and the cost detail last. Nothing is redundant, though the 'Canonical' framing is slightly promotional and does no routing work.

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-param tool with no annotations and no output schema, the description does state what is returned, which partly fills the gap. It still leaves the chain default, address format expectations, and cost-on-failure behavior unaddressed, so an agent has open questions before invoking.

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 0%, so the description must compensate. It maps the chain parameter to 'Base or Ethereum' and implies the address is a single wallet address, adding meaning beyond the bare enum and regex. It does not clarify which enum value is the default or confirm the address format, so compensation is partial.

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 (Returns) and resource (native ETH and USDC balances for one address) scoped to Base or Ethereum. However, it never distinguishes itself from the many sibling balance tools (chain-native-balance, chain-erc20-balance, chain-live-balance), so an agent cannot tell why to pick this 'canonical' one over those without opening schemas.

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?

'Suitable for recurring wallet and treasury polling' gives an intended-use signal that implies fit for monitoring/treasury siblings. But there is no explicit when-to-use vs when-not, and no alternative named for one-off or non-polling balance reads, leaving the agent to infer.

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