check_breach

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

Discloses underlying data source (HIBP), scale (13B+ accounts), and pricing model (pay-as-you-go $0.10 USDC, subscription option). No annotations exist, so description compensates well, though rate limits or error handling are omitted.

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 plus pricing note—no fluff. Could merge some details, but overall efficient. Front-loaded with core purpose and key contextual info.

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?

Given no output schema, description explains return value (breach count and details including name, date, data classes). Also covers use case, source, and cost. Lacks info on invalid email handling, but still robust for a simple tool.

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 covers the single 'email' parameter with format and description (100% coverage). Description adds no additional parameter-level semantics beyond context about the service; baseline of 3 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?

The description clearly states the action ('Check whether an email address appears in known data breaches'), the resource (email address against HIBP database), and differentiates from sibling tools like 'check_domain_lookalikes' which target different entities.

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 recommends use 'before allowing high-risk actions that depend on credential integrity', providing clear context. No explicit exclusion criteria or alternatives, but the sibling list implicitly defines other check contexts.

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