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

Annotations already declare readOnlyHint=true, openWorldHint=true, and idempotentHint=true, covering mutation safety. The description adds valuable behavioral disclosures: it returns only metadata (no contents), notes that large pages are heavy for an agent loop (in the limit param), and explains offset semantics for reaching the tail of a ~16k-post archive. This goes well beyond the annotations.

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 concise yet information-dense, with the core action ('Search the FULL historical breach archive') front-loaded. Every sentence earns its place: sources, filter capabilities, return-type limitation, and concrete example queries. It is well-structured and does not over-elaborate.

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 complexity (9 parameters, multiple sources, no output schema), the description is remarkably complete. It covers the full date range, data sources, filter dimensions, return scope, and even performance guidance for large pages. The absence of an output schema is mitigated by 'Returns disclosure metadata only', which sets clear expectations for the agent.

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 baseline is 3. The description provides a high-level summary of filter types ('keyword, year range, sector, exposed data type or minimum scale') and ordering ('by date or size'), but this does not add meaningful detail beyond what is already in the schema parameter descriptions. Thus, no score above baseline is warranted.

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 explicitly states the tool searches the FULL historical breach archive, enumerates specific data sources (HIBP, ransomwatch, RansomLook, SEC filings), and clarifies it returns disclosure metadata only. This clearly distinguishes breach_history from sibling tools like breach_news or breach_stats by emphasizing the historical, archive-wide scope. Examples ('biggest breaches of 2013') further anchor its purpose.

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 provides clear usage context with 'Use this for questions like...' and defines what it does not return ('never breach contents'). However, it does not explicitly name alternatives or state when to prefer other sibling tools, so it falls short of a 5 which requires explicit when-not/alternatives.

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