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

With no annotations provided, the description carries the behavioral burden. 'Public HIBP breach metadata' does useful work by signaling a read-only, non-sensitive lookup rather than an email breach lookup. However, it does not disclose authentication needs, rate limits, live-fetch behavior, or what the search actually returns beyond 'metadata.'

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 extremely lean, with no filler and the 'Breach Catalog' context front-loaded. It earns near-top marks for brevity, but it is a fragment rather than a structured, informative description, so it falls short of a 5.

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 the tool's simplicity—one optional parameter and an output schema—the core scope is minimally viable. But the description is not complete enough for reliable selection among many breach-related siblings, and the lack of q semantics leaves an invocation gap.

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 0%, and the description does not explain the 'q' parameter's matching semantics—whether it searches breach names, domains, dates, or something else. The word 'search' only weakly implies that q is a query string, which is insufficient compensation for an undocumented single parameter.

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 identifies a specific action and resource: searching 'public HIBP breach metadata.' This is clear and source-specific. However, it does not distinguish itself from related siblings such as hibp_breaches or breachdb, and it reads more like a catalog label than a full statement of behavior.

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?

There is no guidance on when to use this tool versus alternatives like hibp_breaches, breachdb, or breachdirectory. The description neither names alternatives nor gives conditions for choosing this tool, so an agent has to infer usage from the name and the single-word phrase.

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