breachPastes

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

Annotations already declare readOnlyHint/openWorldHint/destructiveHint=false, so safety is covered. The description adds meaningful behavioral context beyond that: the operation is gated behind a paid HIBP API key, which is genuine operational information an agent needs.

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 tight sentences, purpose front-loaded, with the prerequisite requirement following immediately. Every phrase earns its place.

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 one-parameter read lookup with annotations covering safety and an existing output-format expectation, the description covers purpose and the auth/cost gate. The main omission is any cross-reference to the closely related breachSearch/breachPassword siblings.

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% for the single email parameter, so the schema already carries the semantics. The description adds no format, matching, or normalization detail beyond what the schema provides.

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+resource ('Search for an email address in publicly posted pastes') and names the data source (Pastebin, via HaveIBeenPwned). The focus on *pastes* rather than breach dumps implicitly distinguishes it from siblings like breachSearch, though it never names that sibling explicitly.

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 a real prerequisite ('Requires HIBP_API_KEY (paid endpoint)'), which is useful context, but gives no when-to-use vs when-not guidance and does not point to breachSearch or breachPassword as alternatives for related lookups.

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