Retrieve one customer

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

No annotations are provided, so the description carries the behavioral burden. It explicitly says 'Read-only' and describes that the result includes Links, which gives an agent useful safety and response-shape information. It does not specify missing-customer behavior or auth requirements, but for a simple getter this is a minor gap.

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 sentences with no filler: the first states what is retrieved and by what key, the second adds safety and a use case. It is front-loaded and every sentence contributes.

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?

Given the low complexity, full schema coverage, and no output schema, the description covers the main identifier, the Links in the response, read-only behavior, and a concrete use case. It falls slightly short on error or not-found semantics, but overall it gives an agent enough to call 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 description coverage is 100%, so the baseline is 3. The description adds mild context by referring to customer_ref as the 'reference shared with the merchant's application (ReferenceCustomer)', but it doesn't materially explain offer_ref beyond what the schema already provides.

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 action with a clear resource: 'Retrieves a ProAbono customer by the reference shared with the merchant's application.' It also adds the distinguishing detail that the response includes hosted-page Links, separating it from sibling tools like create_customer or update_customer.

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 description gives an explicit use case: 'Use it to check whether a logged-in user already exists as a ProAbono customer.' It doesn't mention when not to use it or name alternative tools, but the context is clear enough for an agent to choose it appropriately.

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