Create or update a ProAbono customer (write)

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

With no annotations, the description carries the full burden and does well: 'WRITE', idempotent upsert behavior, 'Only the fields passed are written', and the warning that name/language can be overwritten by hosted pages. It stops short of covering auth requirements, error modes, or response shape, but the key behavioral traits are 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?

Four sentences deliver a lot: action, upsert semantics, use cases, partial update, and a critical warning. It is front-loaded with 'WRITE. Creates...' and every sentence earns its place with 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?

For a write tool with no output schema and five parameters, it provides enough context for correct invocation: when to use, upsert behavior, partial update, and the hosted-pages overwrite pitfall. It omits response/error details, but those are secondary to calling the tool correctly.

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 baseline is 3. The description adds real value by stating partial-write semantics and warning about field authority, directly affecting how name and language should be handled. It does not need to repeat schema details, but the added guidance pushes it above baseline.

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 opens with 'Creates a ProAbono customer... or updates it when one already carries that reference' and explicitly calls out the upsert keyed on ReferenceCustomer. This makes the tool's dual create/update job unambiguous and distinguishes it from read-only siblings like get_customer and update_billing_address.

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?

It gives concrete trigger points: 'first provisioning at sign-up or first login' and 'every later change', with a rationale about hosted pages and rights reads. It does not explicitly name alternative tools or state when not to use it beyond the field-authority caution, so it misses the top tier by a small margin.

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