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

Annotations cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description layers on valuable context they do not convey: no sign-in required, newest-incident-date-first ordering, the lack of a date filter with a prescribed fallback behavior, and the coverage limit that this is one vendor's catalog rather than all breaches worldwide.

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?

Front-loaded with the trigger and purpose, and every sentence carries distinct information (auth, ordering, no-filter caveat, scope limit, exclusions). It is dense and enumerates return fields already covered by the output schema, which is slight redundancy, but 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?

For a single-parameter read-only lookup with an output schema, the description covers everything an agent needs: when to call it, that no auth is required, what is returned, ordering, the absence of filtering, and the catalog's coverage limits. Nothing material is missing.

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% and the single 'limit' parameter carries its own description with default and range, so the schema does the work. The tool description never mentions the limit control or how it interacts with the 'newest first' ordering, so it adds no parameter meaning beyond the schema. Baseline 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 names a specific verb and resource ('Returns the newest breaches in LeakData's public catalog') and states ordering, returned fields and scope boundaries. It explicitly carves itself out from siblings like search and from adjacent news domains, so an agent can select it without opening the schema.

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?

It gives a concrete trigger ('when someone asks which data breaches happened recently'), an explicit exclusion ('Not for general security, ransomware or vulnerability news'), and an operational caveat: there is no date filter, so the agent must inspect returned dates and report when none match the requested period.

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