exposure_check

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

With no annotations at all, the description carries the full behavioral burden and does well: it discloses that results are aggregates only, never passwords or personal records, and that the call costs 0.03 USDC on Base via x402. It does not cover failure modes, caching, or rate limits, which keeps it from a 5.

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 sentence, densely front-loaded with the core purpose before the data details and cost parenthesis. It earns its length by packing in return contents and payment terms, though the long dash/parenthesis structure makes it slightly harder to parse at a glance.

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?

No output schema exists, so the description must describe returns itself, and it does: credential entries with last-seen dates and malware families, leak records, and official breaches, with the aggregate-only privacy guarantee. Cost is also disclosed. What remains thin is error/failure behavior, but for a lookup tool this is nearly complete.

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%, so both parameters (domain and confirmNewPurchase) are already fully documented in the schema, including the 'target'/'url' aliases and the purchase-confirmation warning. The description adds no parameter-level information beyond what the schema provides, so the baseline 3 applies.

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 operation (leak/infostealer exposure check) on a specific resource (a domain), then enumerates the concrete data categories returned (stealer-log credentials, leak records, official breaches). This is clearly distinguishable from the sibling exposure_check_email, which operates on an email rather than a domain.

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 purpose statement: an agent can infer to call this when it needs domain-level exposure data, and the domain-vs-email sibling split is inferable but never stated explicitly. There is no explicit when-to-use, when-not-to-use, or alternative-tool guidance.

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