update_payment_method

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

Annotations only declare idempotentHint=true, so the description must carry the mutation semantics: it does partly by stating only changed fields should be sent (patch-style behavior) and by specifying the e-invoice fields. It does not say whether modifying a method used on already-issued invoices has side effects, what permissions are required, or what is returned.

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 compact sentences, front-loaded with the action and scope, then the e-invoice specifics. Dense but every clause carries information; no filler.

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?

Reasonable for a mutation tool with a free-form nested 'data' object and only idempotentHint as annotation coverage: the core patch and e-invoice instructions are present. It still leaves the identifier semantics, valid data keys beyond the two named ones, and the effect on existing documents undocumented, and there is no output schema to lean 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 only 33% schema coverage, the description must compensate: it does meaningfully for the opaque free-form 'data' object by naming ei_payment_method and the details:[{title, description}] structure, and by implying patch semantics. The required 'id' parameter is never explained and the set of valid 'data' keys remains open-ended.

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: 'Modifica un metodo di pagamento mostrato in fattura', with a concrete example (bonifico con IBAN). This clearly separates it from update_payment_account, which concerns the account rather than the invoice-level method, though the sibling is never named explicitly.

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?

Gives a useful partial-update instruction ('passa solo i campi da cambiare') and a conditional path for electronic invoices (set ei_payment_method and details). However, it offers no when-not guidance, no prerequisites, and no routing to create_payment_method or update_payment_account for related cases.

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