chainpeek: get native and ERC-20 balances of an address

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

Goes well beyond the annotations (readOnly/idempotent/openWorld) by disclosing partial-failure semantics (a non-ERC-20 entry returns ok:false with its error while the call still succeeds), 5xx behavior for malformed node answers and that such calls are not charged, latency (0.3-2 s), price ($0.004), the free tier (10 chain reads per IP per UTC day), and a prompt-injection warning about attacker-controlled token symbols. This is unusually complete behavioral disclosure.

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-loads purpose and routing before edge cases, security notes, and pricing; nearly every sentence carries distinct information. It is long, and the 'without tokens' clause duplicates the schema default, so it is dense rather than perfectly lean.

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?

With an output schema present, return-value shape need not be described, and the description still covers chains, batch limits, partial failure, cost/quota, error behavior, and safety caveats. An agent has everything needed to call this correctly and interpret failures.

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 the baseline is 3, but the description adds meaning the schema lacks: the failure mode for a non-ERC-20 address in `tokens`, the 20-entry cap as a hard behavioral limit, and the untrusted nature of returned symbols. It slightly restates the schema's 'omit for native balance only', which keeps it from a 5.

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 (read), the exact resources (native balance and up to 20 ERC-20 balances of an address), the supported chains, and the batching scope in one call. It explicitly names the sibling tools it is not (get_balance, get_erc20_transfers, get_solana_token_balances), so an agent can route without opening any 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?

Gives explicit alternatives with the selecting condition: single balance → get_balance, transfer history → get_erc20_transfers, Solana → get_solana_token_balances. It also states the within-tool condition for the optional parameter (without `tokens` only the native balance is read). Nothing is left to inference.

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