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

The description gives meaningful behavior details beyond the read/idempotent annotations: cursor-based pagination, a max of 20 results per page, the presence of first/last names, and a cost of 10 Zooq credits. This is valuable operational transparency.

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 short and dense, leading with the core behavior and immediately covering the important operational facts. Each clause earns its place, 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?

Given that this is a simple paging routine, the description covers the essential runtime aspects: pagination mode, page size, cost, and returned name attributes. Remaining details like the shape of cursor strings are appropriately delegated to the parameter schema, so an agent has enough to invoke the tool correctly.

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 input schema already provides 100% coverage with descriptions for domain, cursor, and kind (including the accepted values). The description adds no additional parameter-level nuances, so it meets the baseline for schema-covered tools, but doesn't improve beyond it.

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 specifies a clear verb and target: 'Page emails already known for a company domain.' This sets it apart from sibling tools like email_find and email_verify by emphasizing existing/known email records instead of discovery or validation. The intent is unambiguous.

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 phrase 'already known for a company domain' implies the appropriate context (when you already have a domain and need its stored contact addresses). However, the description never explicitly contrasts this with email_find, email_verify, or other nearby alternatives, so the usage guidance is more inferred than spelled out.

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