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

With no annotations, the description carries full responsibility for behavioral disclosure. It doesn't state whether the tool uses public data, verifies addresses, returns single or multiple patterns, or requires at least one name. The phrase 'generate likely email patterns' hints at non-verification but doesn't explicitly disclose limitations.

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 concise sentence that immediately communicates the tool's function. It is appropriately sized for the tool's simplicity and contains 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 tool is simple (3 optional params, no output schema), and the description is minimally adequate. However, it lacks context about how optional parameters interact, likely output format, and differentiation from sibling tools. Given the simplicity, a score of 3 seems appropriate.

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%, with each parameter having a clear description. The tool description adds no extra meaning beyond what the schema provides, but the baseline is 3 when parameters are fully described.

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 ('Generate') and identifies the resource ('likely email patterns') and target ('person at a domain'). It clearly distinguishes from siblings like 'company_lookup' and 'domain_info' by focusing on email pattern generation. However, it doesn't explicitly contrast with 'person_search', which could also involve finding emails.

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 on when to use this tool versus alternatives. It doesn't mention scenarios where this tool is preferred over 'person_search' or 'domain_info'. The intended use is only implied by the name and description.

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