Token Balance

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, openWorld), so the bar is lower. The description still adds real value beyond them: it discloses that the result comes back in two forms (decimals-adjusted and raw) and pins the chain to Base, plus the address literal format.

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?

Two sentences, front-loaded with the core capability and the output shape, followed by an actionable example. Slight redundancy: the '0x + 40 hex' constraint is repeated verbatim from the two schema parameter descriptions.

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 simple two-address read with an output schema, the description gives chain, address format, result formatting, and a valid example — enough to invoke correctly. Only minor gaps remain (e.g., behavior on a non-ERC-20 or wrong-chain address), which edge cases rarely determine selection.

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%, so both parameters are already fully documented in the schema; baseline is 3. The description restates the 0x + 40 hex format and adds a worked USDC example, which is marginally useful but largely duplicates the schema text.

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 concrete operation (read how much of a specific ERC-20 token a specific wallet holds) with an explicit scope (Base, fixed token+holder pair). This is intrinsically distinguishable from token_info (token metadata) and address_report (broader wallet view), so an agent can route correctly without opening a schema.

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 explains how to fill the parameters but never says when to choose this tool over address_report or token_info, nor when it is not appropriate. No preconditions, no exclusions, no named alternatives are given.

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