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

Annotations already cover readOnly/openWorld/idempotent/destructive, so the safety profile is handled. The description adds useful context beyond that: the data source (statutory Payment Practices reports), the derived nature of the output (computed interest and fixed compensation), and the edge-case behavior that a non-reporting company is explicitly stated. It doesn't mention latency, freshness, or output format details.

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?

The purpose is front-loaded and information-dense, but the phrasing is run-on and the idea of 'what lateness is worth on your invoice' is stated twice ('what its lateness is worth on your invoice' and 'statutory interest plus fixed compensation its typical lateness is worth on an invoice of your size'). That redundancy and the heavy dash-clause structure cost some efficiency.

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?

With no output schema, the description carries the job of describing return values, and it does so reasonably: it lists the metrics returned and the derived compensation/interest figures, plus the non-reporting edge case. It is largely complete for a read-only analytical tool, though it could say more about the shape or units of the returned data.

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 all three parameters and the baseline would be 3. The description adds meaning by explaining how the parameters are used — 'typical days to pay against your terms' and 'on an invoice of your size' — clarifying that terms and invoice feed a computation rather than being arbitrary inputs.

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 states a specific subject (a company's payment habits from its statutory Payment Practices reports) and enumerates the outputs (typical days to pay, share paid late/past 60 days, trend, statutory interest plus fixed compensation). It's clear what the tool does, but it never differentiates itself from close siblings like 'late_payment' and 'payment_practices', which sound like they may overlap.

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 or when-not-to-use guidance, and no named alternative among the many siblings (late_payment, payment_practices, distress_signals) that could plausibly cover the same question. The only usage-ish note is the edge case that a non-reporting company is flagged, which is behavioral rather than routing guidance.

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