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

With no annotations provided, the description carries the full burden of behavioral disclosure, but it only conveys a read-only lookup. It does not mention API limits, data source caveats, error behavior, or what a breach hit actually means, leaving significant behavioral ambiguity.

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 a single front-loaded sentence with no filler or redundancy. It is appropriately brief for a simple one-parameter tool, though the brevity comes at the cost of missing usage context.

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 tool with no annotations and heavy sibling ambiguity, the description is too thin to be a complete guide. An agent cannot reliably choose this over other breach-checking tools or understand behavioral constraints; the existing output schema helps with return structure but not with usage context.

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 schema exposes only a bare string `q` with no description and 0% schema coverage. The description adds the meaningful hint that `q` is an email or username, but it does not specify accepted formats, normalization, or how the default empty value behaves, so the semantic coverage is only partial.

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 states a specific action ('Check') and resource ('breach database') and identifies the query target as 'email/username exposure,' so an agent can tell what the tool does. However, it does not differentiate itself from the many breach-related siblings such as hibp_email, breachdb, breachsearch, or leakcheck, so it stops short of a 5.

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?

No guidance is given about when to use this tool versus alternatives like hibp, hibp_email, breachdb, or breach_aggregator. There are no exclusions, prerequisites, or conditions, so an agent must infer usage from the tool name alone.

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