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

Annotations already cover readOnly/non-destructive, and the description adds real context beyond them: output is aggregates only, scoped to a single accepted client, and returns only blocking points/warnings rather than advice. It does not mention what happens if the client is not accepted or if the period has no data, but the behavioural profile is well disclosed.

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?

Front-loads the account type and subject ('For a gestoría account: the figures of ONE accepted client'), then lists the returned figures, then the scope caveat. Dense but every clause carries signal; slightly long as a single run-on enumeration.

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?

There is no output schema, so the description shoulders the return-value burden and does it well by naming the invoice, expense and revision aggregates in order. Remaining gaps (behaviour for a non-accepted client, empty periods) are minor for a read-only aggregation tool.

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% and both year and quarter already carry descriptions, so baseline 3 applies. The description reinforces the period semantics ('a year or a quarter') and implies link_id identifies the client rather than the tenant, but adds no new format or default information.

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 pair ('the figures of ONE accepted client for a year or a quarter') and enumerates exactly which figures: invoice counts, net base, IVA repercutido, IRPF, totals, drafts, expenses with IVA soportado, blocking points and warnings. This cleanly separates it from siblings like gestoria_facturas_mandante (line-level invoices) or gestoria_revision_mandante (the revision itself) — it is the aggregate roll-up.

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?

Implies usage through context ('For a gestoría account', 'ONE accepted client') and the scope fence 'Sums and counts only, never an opinion on what to declare or deduct'. It never explicitly says when to prefer this over gestoria_revision_mandante or gestoria_gastos_mandante for the same client/period, so routing still needs inference.

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