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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower. The description usefully enumerates the returned aggregate fields, but says nothing about permissions, business scoping rules, or whether the pay run must be in a particular state.

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 short, front-loaded sentences: the payload contents come first and the raw REST path second. The endpoint path is mild noise for an agent but does map the tool to the underlying API route.

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 two-parameter getter with no output schema, the description discloses the key aggregate values returned (hours, gross, net) and the required ids are fully specified in the schema. Only the shape of the rest of the payload and any scoping constraints remain unstated.

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% (both ids documented, with business_id even pointing at keypay_list_businesses), so the schema carries the parameter burden. The description adds no format or constraint detail beyond that, making the baseline 3 appropriate.

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 and resource ('One pay run with its total hours, gross wages and net wages'), which separates it from keypay_list_pay_run_summaries. It does not, however, explicitly distinguish itself from the similarly named keypay_get_pay_run_totals, so an agent comparing those two siblings gets no help.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as keypay_get_pay_run_totals or keypay_get_pay_run. The agent must infer usage purely from the name and the summary fields listed.

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