verify_claim

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

No annotations are present, so the description carries the full burden—and it delivers. It discloses the payment requirement, latency, the offline signature-verification behavior against the pinned published key, and the verdict/confidence/stances outputs. This is comprehensive behavioral disclosure for a zero-annotation tool.

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?

A single dense paragraph, properly front-loaded with the core purpose ('Verify one factual claim') before cost and return details. Every clause earns its place—cost, latency, outputs, and evidence semantics—with no filler. It could be slightly more structured, but it remains efficient for the information carried.

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 no output schema and no annotations, the description must fully explain return format and behavior, and it does—listing all return fields (verdict, confidence, stances, receipt id, settlement transaction, signature verification) plus cost and latency. Nothing an agent needs to call this 2-param tool correctly is missing.

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 0%, so the description must compensate. It fully explains `evidence` (strings the caller already holds, admitted as secondary-tier evidence) beyond the bare schema type. The `claim` parameter is only described as 'one factual claim'; its expected format is not elaborated, leaving a minor semantic gap.

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 and resource ('Verify one factual claim') and enumerates its concrete outputs (verdict, calibrated confidence, per-source stances, receipt id, settlement transaction, signature verification). It is clearly distinguishable from siblings quote and service_status, which are obviously different operations, so an agent can route correctly from the description alone.

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?

Provides clear context on when this is appropriate: it is a paid call ($0.05 USDC over x402), takes 5-15 seconds, and the optional `evidence` parameter's role is explained. It does not name a sibling alternative or state when-not-to-use, but quote and service_status differ enough that no routing ambiguity exists, so the absence of exclusions is not a meaningful gap.

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