breachList

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

With no annotations, the description partially carries the burden by stating 'Free endpoint, no API key required,' which is a useful access trait. However, it omits other behavioral details such as pagination, rate limits, or potential response size, leaving some uncertainty about using a tool that lists all breaches.

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 only three short sentences: the main action first, then the optional filter, then the access note. Every sentence adds information and there is no 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?

The description covers the core function and the optional filter, and the free endpoint note is helpful. However, it lacks guidance on choosing alternatives like breachLatest for recency or handling potentially large responses, which is a clear gap for a list-all tool.

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 coverage is 100% for the only parameter 'domain', and the schema already provides a description and example. The tool description only repeats the filter option without adding new semantic details, so the baseline of 3 applies.

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 ('List') and resource ('all known data breaches from HaveIBeenPwned'), with optional domain filtering. This clearly distinguishes from sibling tools like breachSearch (search) and breachGet (specific breach).

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 implies the main use case (listing all breaches) and shows how to filter by domain, but it does not explicitly compare with alternatives or state when not to use the tool. The 'Free endpoint, no API key required' note adds access context but not usage guidance.

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