dp_check_domain_breachesCheck whether a domain appears in known public data breaches (via the Have I Been Pwned breach catalog). Returns matching breaches with dates, exposed data classes, and account counts. Domain-level only — no personal email is queried.
| Name | Required | Description | Default |
|---|---|---|---|
| domain | Yes | Domain to check, e.g. 'example.com'. |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so the description adds valuable context by detailing the returned data (dates, exposed data classes, account counts) and the domain-only scope. This goes beyond the annotations, though it omits potential limitations like rate limits or data freshness.
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?
The description is two sentences, front-loaded with the core purpose, then return details, then a scope qualifier. Every sentence earns its place with no redundancy or 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 simple tool with one parameter, no output schema, and basic annotations, the description covers all essential aspects: purpose, return value composition, and scope limitation. It adequately prepares an agent to understand what the tool does and what results to expect.
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?
The input schema already fully describes the single 'domain' parameter with 100% coverage, so the description adds little beyond the schema. It reiterates domain-level scope but does not introduce new parameter-related detail, aligning with the baseline score for high schema coverage.
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 tool's function: checking if a domain appears in known public data breaches via HIBP. It also distinguishes from siblings by explicitly noting 'domain-level only — no personal email is queried', which differentiates it from email/password-focused tools.
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?
The description provides clear context for when to use the tool (domain-level breach checks) and hints at exclusions by stating 'no personal email is queried', implying that email-level lookups belong elsewhere. However, it does not explicitly name alternative sibling tools or state when-not-to-use conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.