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

readOnlyHint=true already covers the safety profile, and the description adds genuinely useful context by disclosing the returned fields of each schedule even though no output schema exists. It does not cover pagination behavior, but the schema's own parameter descriptions already explain next_cursor/truncated/total semantics.

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 sentences, no filler, with the resource scope and returned fields front-loaded and the sibling routing pointer placed at the end where it belongs. Every clause carries information an agent would otherwise have to infer.

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 two-parameter read-only list with no output schema, the description does the heavy lifting by enumerating the fields of each schedule row. It stops short of explaining the semantics of the flags it names (e.g. what 'enabled' or 'what happens on the pay date' concretely mean), which leaves a small gap given there is no output schema to fall back on.

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?

With 100% schema description coverage, both `limit` and `cursor` are fully documented in the schema, including the default of 50 and the cursor round-trip. The description adds no parameter-level detail beyond that, so the baseline of 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+resource ('List the business's pay run schedules') and enumerates exactly what each row carries: enabled flag, frequency, pay day, next run, payslip population, and pay-date behavior. It also explicitly disambiguates from the closely-named sibling list_payruns by scoping that tool to the runs a schedule produced.

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?

Provides a clear routing rule: use list_payruns for the runs a schedule generated, implying this tool is for the schedule definitions themselves. It lacks an explicit 'when-not' or prerequisite statement (e.g. whether an empty result means no schedules configured), so it falls short of full when/when-not guidance.

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