getCustomer

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, openWorldHint=true. The description adds value by listing the contents of the returned customer object (name, contact, address, points, rank) and confirming it works for both members and non-members. No contradictions with annotations.

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 a single, well-organized paragraph. It front-loads the main purpose, then immediately states the return fields, usage context, and explicit alternatives. Every sentence adds value without 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?

Given the tool's simplicity (one required param, no output schema, no nested objects), the description covers purpose, return values, usage guidance, and sibling differentiation. It does not mention error handling or missing customer_id scenarios, but for a read-only idempotent tool, this is acceptable.

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?

Input schema has 0% coverage—no description for customer_id. The description only says '指定した顧客ID' (specified customer ID), which adds minimal meaning. Although the parameter is self-explanatory, the description could have better detailed its format or source. Baseline for low coverage is low, but the simplicity of the parameter prevents a lower score.

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 action: '指定した顧客IDの顧客 1 件を取得します' (get a single customer by ID) and specifies the returned fields. It also distinguishes this tool from siblings like getCustomers, postCustomerPoints, and updateCustomerMembership, 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 explicitly tells when to use this tool ('一覧から特定顧客の詳細を個別に確認する時') and provides clear alternatives for other cases: getCustomers for conditional search, postCustomerPoints for point operations, updateCustomerMembership for rank changes, and even mentions the member parameter of getCustomers for membership filtering.

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