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

Annotations already establish the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description's job is to add context it doesn't already have. It does: overlap/exclusion policy, all-years scope, breakdown dimensions, and the notable behavior that unmatched names return close matches rather than failing.

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 front-loaded sentences with little waste, and the scoping caveats come early. The breakdown list ('source, amount kind, period, native currency and location evidence') is dense but earns its place by describing the return shape in the absence of an output schema.

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 burden of return-shape disclosure and does so via the breakdown enumeration, and the annotations cover safety. Minor gaps remain in what 'included' precisely means and how excluded/unreported values are obtained, but the core invocation picture is complete.

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 100%, so the two parameters are already documented, giving a baseline of 3. The description nonetheless adds meaning beyond the schema by stating that either name or supplier_id is acceptable and that unmatched names fall back to fuzzy close matches, which is not captured in the schema.

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 with scope ('get included reported record values, all years, for a supplier or recipient') and explicitly disambiguates by negating what it is not ('not everything received, unique spending or spending in NL'). It does not name a specific sibling (e.g., get_totals, search), so the differentiation is by description rather than routing.

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?

The negative statements ('These are not everything received, unique spending or spending in NL') give implied when-not boundaries, and it explains how to supply a name or supplier_id. But there is no explicit guidance on when to prefer this over get_totals, get_record, or search, so usage is inferred rather than stated.

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