chainpeek: get an ERC-20 allowance

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

Annotations cover safety (readOnly, idempotent, openWorld, non-destructive), and the description adds context annotations cannot: 422 for non-readable ERC-20, 5xx for malformed node answers, that neither is charged, typical latency 0.2-1s, price $0.002, the 10 free reads/IP/day quota, and a prompt-injection caution about returned on-chain strings.

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?

Purpose and the sibling routing are front-loaded in the first two sentences; the rest is dense but each clause carries distinct operational value (error codes, price, quota, security note). Slightly run-on, but nothing is 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 paid, cross-chain read tool this covers everything an agent needs: scope, alternative, failure semantics, cost, rate limit, latency, and an output-trust warning. An output schema exists, so return-shape explanation is correctly omitted.

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 100% with regex patterns and an enum, so all four parameters are already fully documented. The description adds only the chain list, which duplicates the enum. Baseline 3 is appropriate.

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) and resource (ERC-20 allowance) plus the exact supported chains, and names the sibling to use for a different need (audit_token_approvals). An agent can tell it apart from get_balance or audit_token_approvals 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?

Explicitly routes the alternative case: 'For every live approval of a wallet use audit_token_approvals.' Combined with chain scope and the free-tier/price note, the agent knows when this tool is the right call and when it is not.

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