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

Annotations already indicate read-only, idempotent, non-destructive behavior, so the description's main job is to add context beyond that. It does: it discloses the subscription requirement and clarifies that results are historical and 'do not establish current account access,' which is valuable for interpreting the data's reliability. No contradiction with annotations exists.

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 earn their place: the first states the core function and output, and the second adds the prerequisite and an important interpretive caveat. The information is front-loaded and there is 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 read-only tool with full parameter schema coverage, an output schema, and annotations, the description is nearly complete. It covers purpose, prerequisite, and data semantics. The only missing piece is explicit routing guidance relative to sibling stealer-log tools, but that is a minor gap given the clear resource naming.

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 the schema already documents all four parameters (domain, limit, offset, response_format). The description adds no additional parameter-level detail; it only restates the domain-oriented purpose. This matches the baseline for full 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 uses a specific verb ('Return') and a specific resource ('stealer logs for an email domain'), and clarifies what is returned ('email aliases and associated website domains'). The phrase 'for an email domain' distinguishes it from sibling tools like hibp_get_stealer_logs_by_email and hibp_get_stealer_logs_by_website_domain, even though those are not named.

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 gives clear context: it is a domain-scoped stealer-log lookup, requires an OAuth-linked subscription, and carries a security caveat. However, it never explicitly says when to prefer this tool over the closely related email-address or website-domain variants, nor does it state any exclusions. Usage is implied by the domain-focused wording rather than made explicit.

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