Update customer

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

With no annotations, the description carries the full burden and does disclose non-obvious behavior: it is a partial PATCH rather than a replace, and phone/birth_date are returned by the API but not writable. It does not cover auth/permission requirements, idempotency, or failure behavior, so it is strong but not complete.

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 tight sentences, front-loaded with the operation and its field constraints, then the read-only warning, then the escape hatch to get_operation_schema. Every sentence earns its place with no redundancy.

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 mutation tool with a nested opaque parameter, no annotations, and no output schema, the description supplies the critical field-level constraints and a path to the full request shape. It omits response/permission expectations, which are minor given the pointer to get_operation_schema.

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%, but the 'customer' parameter is an opaque object with additionalProperties, so the schema alone tells the agent nothing about valid keys. The description enumerates the writable fields (note, first_name, last_name, email) and explicitly excludes phone/birth_date, adding real meaning beyond 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 and resource ('Update a customer') and immediately narrows scope with the exact set of writable fields, which cleanly separates it from get_customer/list_customers and from create-type siblings. The '(plain JSON PATCH)' qualifier further pins down the operation type.

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 concrete when-to-use constraints: which fields are updatable, which are read-only and must not be attempted, and a prerequisite pointer to get_operation_schema("UpdateCustomer") for the request shape. It lacks an explicit contrast with alternatives such as create_customer or bulk update paths, so it falls short of a 5.

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