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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the bar is lower. The description still adds real value: newest-first ordering, a fixed page size of 100, and the required permission scope — none of which appear in the annotations or schema.

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?

Three short sentences with no waste: what it returns and its ordering first, then the auth requirement, then pagination. Front-loaded and fully earned.

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 2-parameter, no-output-schema read tool, this covers scope, permission, ordering, page size and pagination mechanics. Only the meaning/format of the before cursor and the shape of an enquiry are left implicit.

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 0%, so the description must carry the burden, and it does: both parameters are explained as cursor inputs taken from the last enquiry to page to older records. It doesn't specify that before is a timestamp in milliseconds, leaving the integer format ambiguous.

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?

States a specific verb+resource: read enquiries sent through the owner's website, with ordering and page size. It distinguishes itself from siblings like leads_summary and list_contacts by naming the resource, though it doesn't explicitly contrast with them.

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?

Gives clear context: requires leads:read scope, and tells the agent how to page backwards using before and cursorId from the last enquiry. No explicit when-not or named alternatives (e.g., leads_summary for aggregates), so it stops short of a 5.

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