postCustomers

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

Annotations already declare readOnlyHint=false and destructiveHint=true. The description confirms creation and return of the customer object, but adds no additional behavioral context (e.g., idempotency, side effects). It does not contradict annotations, but the value added beyond annotations is limited.

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?

The description is two concise sentences in Japanese, with no redundant information. It front-loads the core purpose and immediately adds sibling tool references. Every sentence serves a clear purpose.

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 complexity (1 nested parameter with many sub-properties, no output schema), the description is moderately complete. It explains the return value and references sibling tools, but does not cover all parameters, error handling, or idempotency. More detail on optional fields and potential duplicates would improve completeness.

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 0% for the top-level parameter, placing the burden on the description. The description explains required fields (name, mail, pref_id, postal, address1, tel) and the add_member flag, but omits many optional fields like fax, busho, hojin, address2, furigana, etc. The schema’s nested descriptions help, but the description should be more comprehensive.

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 clearly states the verb and resource: '新規顧客をショップに登録し' (register a new customer in the shop). It also distinguishes from sibling tools by explicitly mentioning updateCustomers, getCustomer, and getCustomers for other operations, making the purpose unambiguous.

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 provides explicit alternatives: updateCustomers for updates, getCustomer for retrieval, getCustomers for search. It also explains how to register as a member vs non-member via the add_member parameter. It lacks a clear 'when not to use' statement but the context is well-defined.

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