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

Annotations already provide the safety profile (readOnlyHint, idempotentHint, non-destructive). The description adds a pagination cap and the verification-status filtering angle, but it mostly restates schema constraints and does not disclose additional behaviors such as default ordering or whether leads are de-duplicated.

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?

Two efficient sentences with no filler. The core scope and limit are front-loaded, and the filtering purpose is stated in the second sentence, making the description easy to parse quickly.

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 simple read-only list tool with 100% schema coverage and robust annotations, the description covers the essential scope and use case. It lacks details about return shape or pagination semantics, but those are partly covered by the schema and the tool's low complexity.

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 schema already documents limit, offset, list_id, and email_status. The description adds some context by explaining that email_status filters to what a campaign would actually send, but it does not meaningfully enrich the other parameters beyond the schema.

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 clearly states the tool reads leads contained in one specific list and imposes a 200-per-call cap, which distinguishes it from broader lead-reading tools like crm_leads or preview_b2b_leads. It is more specific than the title alone because it identifies scope and a practical filtering use case.

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 second sentence gives a concrete use case: filter by verification status to see what a campaign would actually send to. This implies when the tool is useful, though it does not explicitly name sibling alternatives or state when another tool should be used instead.

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