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

With no annotations, the description carries the full behavioral burden, and it does meaningful work: it discloses the per-call price ($0.005), the payment rail (x402, USDC on Base), and the response's provenance chain plus Ed25519 attestation. It stops short of describing failure behavior on unpaid calls, rate limits, or whether any data is cached/refreshed.

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 what the tool returns and keyed on the identifier; the second sentence bundles pricing and response-trust details without padding. Dense and largely waste-free, though price and attestation could be split for faster scanning.

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 read tool with no annotations and no output schema, the description usefully lists the returned fields and covers cost/trust. It still omits the expected id format (numeric FDIC cert length vs. the schema's 12-char allowance) and does not define what 'lite' excludes relative to a fuller profile.

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 50%: the schema documents 'payment' but leaves 'id' as a bare string (maxLength 12). The description compensates by specifying that the identifier is an FDIC certificate number, which is genuinely new meaning the schema lacks. The schema already handles the legacy payment header semantics.

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 resource and verb ('US bank profile... by FDIC certificate number') and even enumerates the returned fields (charter class, regulator, headquarters, established date, active status). It clearly differentiates from geographic UK sibling 'uk_company_lookup', but the 'lite' suffix implies a fuller variant whose relationship is never explained.

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 by the resource ('US bank... by FDIC certificate number'), and no sibling overlaps with US bank data, so routing is unambiguous. However, there is no explicit statement of when to reach for this tool, what to do when the FDIC certificate is unknown, or any prerequisite/exclusion guidance.

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