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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds meaningful domain context including 'Pay runs are cycle headers' whose amounts live elsewhere, which prevents an agent from expecting monetary totals. It adds no auth or pagination-caveat detail, but that is a minor gap.

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 tight sentences, front-loaded with the action and return fields, followed by the disambiguating routing notes. Every clause carries information.

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 read-only list tool with no output schema, the description helpfully previews the return fields and clarifies the header-vs-amounts split. Pagination is handled by the schema, so nothing critical is missing, though deeper output-shape detail is absent.

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% and both parameters (limit, cursor) are fully documented with pagination behavior in the schema itself. The description adds no parameter-level detail, so the 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?

States a specific verb (List) and resource (the business's pay runs) and enumerates the returned fields (period window, pay date, frequency, derived status, pay-date action). It explicitly distinguishes itself from two siblings, get_payrun for single runs and list_payslips for amounts.

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?

Names two alternatives with selecting conditions: 'For one run use get_payrun' and 'their amounts live on the payslips (list_payslips)'. This is clear routing guidance, though it doesn't cover other payrun-adjacent siblings like list_payrun_schedules.

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